Msc Nastran 2010 Release Guide 4dgs

---- src | -- SConscript | -- dr3serv | | -- SConscript | | -- r3sgrt.F | | -- r3svald.F | | -- r3svals.F | -- dr3serva | |… | -- other sample dresp3 server directories

Build a DRESP3 Server The simplest way to build a server is to enter the command from the install_dir/msc20101/nast/dr3 directory scons dr3serv where dr3serv is the program name you want to build. The command creates dr3serv on UNIX or dr3serv.exe on Windows. By default, the command saves the program in the directory dr3/Apps/arch/bin

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CHAPTER 5 93 Optimization

that is architecture dependent. For example, arch=LX8664 indicates Linux 64 bit machine or arch=WIN8664 a Window 64 bit machine. If you do not have the write privilege to the install_dir, you have two options: 1. Define APPS_LOCAL and SCA_OBJECT construction variables to redirect the output to another writable location. To learn more about the SCons build environment, please consult Subsection of 'Build External Servers using SCons tools' Under the External Response Section in the DS&O's Guide. 2. Copy the entire dr3 directory to another location that you have the write access to. This option is particularly useful when you want to create your server program in a new subdirectory. Guidelines to Build a DRESP3 Server Building an external server requires your computer to have Software Development Kit installation (SDK) and MSC Nastran installation with the external server option. To create a new server program, you may either work in a new subdirectory under the src to develop required SConscript and Fortran template files or work in an existing subdirectory to modify the required files. If your server program requires additional source codes, you can simply include them in the target directory without the need change in SConscript. However, if you want to add your custom library or object file, you need to place them in the lib/ directory and to update the SConscript file to reference the library and/or object files. To learn more about customizing the SCons build environment and advanced build scenarios, please see Build External Servers using SCons Tool (p. 294) in the Design Sensitivity and Optimization ’s Guide or SCASCons Build System (p. 403) in the SCA Framework ’s Guide.

Using Server Program Consult the External Responses (p. 191) in the Design Sensitivity and Optimization ’s Guide for more information on how to use the server program in a Nastran job.

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94 MSC Nastran 2010 Release Guide Deactivation of Original Design Sensitivity (DSA)

Deactivation of Original Design Sensitivity (DSA) MSC deployed a capability to provide design sensitivities for SOLs 101, 103 and 105 results over 20 years ago. This capability was characterized by a DVAR entry that defined design variables, an associated DVSET that defined the properties that could be varied and a DSCONS entry to define the response and the constraint limits. This capability has been absent from the Quick Reference Guide since the MSC Nastran 2004 release but has still been available in the code. With the release of MSC Nastran 2010, this capability is no longer available. The extensive Design Sensitivity and Optimization capability that is contained in MD/MSC Nastran and that is documented in the MSC Nastran 2010/MSC Nastran 2010 Design Sensitivity and Optimization ’s Guide provides all the functionality of the Original Design Sensitivity Analysis plus many other features as detailed in this document and the ’s Guide.

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Chapter 6: Aeroelasticity

6

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MSC Nastran 2010 Release Guide

Aeroelasticity



Input of Pressures on an Aerodynamic Mesh



Aeroelasticity - Output of Trimmed Loads



CSV Output of Trim Results



SUBCOM/SUBSEQ with Static Aeroelasticity



Upper Hessenberg Complex Eigenanalysis No Longer ed for Flutter Analysis

96 MSC Nastran 2010 Release Guide Aeroelasticity

Input of Pressures on an Aerodynamic Mesh Introduction In MSC Nastran 2010 the can apply pressures at aerodynamic grid (AEGRID) points. Previously, this was not possible.

Benefits It is now possible to input pressures that come from an external source, such as CFD analyses or wind tunnel tests, onto an aerodynamic mesh and Nastran will transform these pressures to forces that can be included in a static aeroelastic analysis.

Feature Description A new Nastran module has been provided that combines information input on the AEPRESS/DMIJ entries with geometry provided on AEGRID/AEQUAD4/AETRIA3 entries and coordinate systems data to produce forces at the aerodynamic mesh points. Spline input can then be used to transfer these forces to structural grid points so that they can be included in a standard SOL 144 static aeroelastic analysis. No new input commands or entries are required to invoke this capability.

Guidelines and Limitations 1. Pressure is input at the grids of the aerodynamic mesh and is converted to forces using the same techniques as are applied with a PLOAD4 entry. That is, the forces are computed using a combination of connected elements (AEQUAD4 and/or AETRIA3 in this case) to define the area over which the pressure is acting in conjunction with systems to determine the direction in which the forces are acting. The forces are computed at the AEGRID locations. 2. Pressure can be input in all three directions at the aerodynamic grid and they do not need to act in a direction normal to the surface. The aerodynamic coordinate system defined by the AEROS Bulk Data entry defines the directions in which the pressures act. 3. There is no aeroelastic effect associated with the AEPRESS input in this case. Only rigid aerodynamic loads are produced. In the example given above, deformations are produced at the structural grid points but there is no aerodynamic correction due to these deformations. 4. It should be apparent that an application of this technique is to input results from a CFD analysis into a Nastran static aeroelastic analysis. To do this, the needs to define the aerodynamic mesh using AEGRID/AEQUAD4/AETRIA3, the pressure vector using a combination of AEPRESS/UXVEC and DMIJ entries and the appropriate spline methods. 5. The AEPRESS data can be used in combination with AEFORCE/AEDW input to directly input aerodynamic forces or downwashes on the same aerodynamic mesh.

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CHAPTER 6 97 Aeroelasticity

6. It is not possible to combine aerodynamic mesh input with Doublet Lattice like aerodynamics in a single run. However, it is possible to have separate meshes using the “RIGID/Flexible Mesh” concepts introduced in MSC Nastran 2005 R3. This entails making an initial run with only the rigid aerodynamic mesh and then, in a subsequent run, attaching the database from this run and using the AERCONFIG case control command to identify the rigid mesh results in a static aeroelastic analysis that would obtain its flexible increments from a doublet lattice based analysis. 7. Currently, this technology is only available in static aeroelasticity (SOL 144 or the ANALYSIS=SAERO option in SOL 200). for SOL 146 (dynamic response) is not provided at this time.

Test Cases The following test cases are available on the TPL in subdirectory /tpl/aero_asm: cyl144b.dat TPL Problem cyl144b.dat TPL file cyl144b.dat provides an example of the loads on a cylinder spinning in an airstream. Textbooks on introductory fluid mechanics such as Chapter 4.8 of Reference 1. provide a closed form solution for this airflow. The aerodynamic mesh is depicted in Figure 6-1. The cylinder has a radius of 1.0 and a length of 10.0. Length units are in inches. Data are input at angles of 22.5 degrees at five spanwise stations ranging from -5.0 to 5.0. The structural model consists of 10 CBAR elements that reference a PBARL entry that creates TUBE cross sections that have an outer radius of 1.0 and an inner radius of 0.95. From the reference, pressure per unit dynamic pressure in a uniform stream can be expressed as: 2

p  q = 4sin  + 2 sin   r  V   +  r  V  

2

where  is the rotation speed in radians/sec. r is the radius of the cylinder and V  is the freestream velocity. The pressure acts radially while Nastran requires input in rectangular coordinates at the grid points. With a coordinate system that has positive x in the direction of the flow and the z axis normal to the flow, the radial pressure at each point has components in the x and z directions. For irrotational flow, the net force in the streamwise direction is zero so that it is only necessary to input the z component of the pressure. Note that 3D effects of the flow are neglected so there is no spanwise component.

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Figure 6-1

The Aerodynamic and Structural Model for the Flow Around a Spinning Cylinder.

A section of the pressure input is given shown in Figure 6-2. The AEPRESS entry identifies a UXVEC entry that indicates the state of the pressure input. In this case, the state includes the intercept and a CIRC value of 0.1, where CIRC is the r  V  parameter. The AEPRESS data at the UXVEC condition is input as a vector using the DMIJ format that lists the grid and component for each real number that provides the pressure at the mesh point. Since the three dimensional aspects of the flow are ignored in this analysis, the same pressure distribution in input at the 5 spanwise cuts.

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aepress 0.45 asymm uxvec 102 intert 1.0 dmij circ1 0 DMIj circ1 1 2 3 4 3 6 3 8 3 10 3 12 3 14 3 16 3

Figure 6-2

asymm

102

circ 0.1 9 1 1 .2866 3.505 3.505 .2866 -.1694 -2.8221 -2.8221 -.16942

circ1 0 1 3 5 7 9 11 13 15 101

0 3 3 3 3 3 3 3 3 3

1 .0 1.6213 4.41 1.6213 0.0 -1.2213 -3.61 -1.2213 0.0

A Portion of the Input Bulk Data that Provides Pressure Data on the Aerodynamic Mesh

Figure 6-3 provides an additional snippet with splining and boundary condition information. The

SPLINE7 is a 6 DOF spline that uses a finite beam technique to connect all the aerodynamic mesh points to the structural grids that are defined along the axis of the tube. The GRDSET entry constrains the motion in the 1256 directions at all the structural grid points while the SPC condition invokes symmetry about the x-axis and the entry allows the tube to move in the 3 direction.

$ $ $ $ aelist

* 6DOF FINITE BEAM SPLINE

EID 101 201 404 set1 101 SPLINE7 100

CAERO 1 thru thru 1001 1

BOX1 thru 216 416 thru 101

spc grdset

1006 3

4

1 1006

Figure 6-3

BOX2 16 301 1011 both

$ $ $

*

SETG 101 thru

DZ thru 316

101

1.0

116 402

401 403

1256

Spline and Boundary Condition Input for the Spinning Cylinder

The goal of the analysis is to determine the rate of rotation necessary to create a lift force that is equal to the weight (URDD3 = 1.0) of the aluminum tube when immersed in an airstream moving at M = .45 (Velocity = 6031.8 inches/sec) at sea level. The .f06 file indicates that the value of the CIRC parameter at “trim” is 1.214E-3. The rotational rate is then 1.214E-3  6031.8   2    = 1.16 cycles/second.

References 1. Kuethe, A.M and Schetzer, J.D., Foundations of Aerodynamics, John Wiley & Sons, New York, Second Edition, 1959.

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GUI Patran Flight Loads SimXpert does not currently aeroelastic analysis.

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Aeroelasticity - Output of Trimmed Loads Introduction MSC Nastran now s the creation of bulk data force/moment entries for trim loads.

Benefits A primary reason for performing a static aeroelastic analysis is to determine the aeroelastic loads acting on the free-flying vehicle. With this new capability it is now possible to output the loads from the trim solution in the familiar FORCE/MOMENT Bulk Data entry format so that these loads could be ed to the group performing detailed stress analysis. In another application, these loads could be viewed in a graphical fashion using, for example, MD Patran.

Input The TRIMF Case Control command is used to invoke this new capability. The can provide an ASSIGN statement to direct the results to a special purpose file, or they will go to the .pch file by default. The TRIMF command is quite flexible in that it can output load components or total loads. It is also possible to limit the output to a set of defined grid points. TRIMF Format: TRIMF    UNIT = i    LOADSET = n   LARGE   INERTIA   APPLIED   AIR   ALL   NOSUM   RIGID  , NOELASTIC   QNORM    =    n 

Example: TRIMF(LOADSET=10001,LARGE)=ALL TRIMF(UNIT=59,INERTIA,NOSUM)=1

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Describer

Meaning

UNIT

Fortran unit to which data are written. (Optional; Default = 7) (punch file).

LOADSET

Load set id for output bulk data entries. If the TRIMF specification results in multiple load sets, then the defined ID will be used for the first and each subsequent load set has an ID incremented by 1. (Optional; Default = 1)

LARGE

Write the output data in large field format (16 characters per field). The default is 8 characters per field.

INERTIA

Write out inertial loads as a separate load set. By default, the separate load set will not be written.


Describer

Meaning

APPLIED

Write out applied loads as a separate load set. By default, the separate load set will not be written.

AIR

Write out aerodynamic loads as a separate load set. By default, the separate load set will not be written.

NOSUM

By default, the sum of the inertial, applied, and aerodynamic loads will be written as a separate load set. This option suppresses the writing of that set of loads.

RIGID

Write out rigid instances of the selected loads (Inertial, Applied, Air and/or Sum) as separate load sets. By default, the separate load set will not be written.

NOELASTIC

By default, the sum of the rigid and elastic increment loads will be written as a separate load set. This option suppresses the writing of that set of loads.

QNORM

Normalize the load by the dynamic pressure used in the trim analysis. By default, the loads are not normalized.

ALL

Loads for all points will be output

n

Set identification of a previously appearing SET command. Only loads on points with identification numbers that appear on this SET command will be output (Integer > 0)

Remark: 1. By default, the loads are written to the punch file (Fortran unit 7). If the specifies an alternate Fortran unit number on the TRIMF entry, by default the loads will be written to a file name that is machine specific (i.e. ‘fort.53’ on many UNIX platforms). The may connect the Fortran unit to a -defined file name by using an ASSIGN entry in the FMS Section of the input file. For example: ASSIGN FILE='load13.inc',STATUS=UNKNOWN,FORMATTED,UNIT=53 2. Up to eight loads sets are available: Rigid Inertial, Rigid Applied, Rigid Air, Rigid Sum and four more with the sum of the rigid and elastic increment. 3. Care must be taken if LOADSET is specified in a run with multiple subcases. There are no checks that the load set IDs which are generated by one subcase are not also used for another subcase. For example, consider the following Case Control commands: SUBCASE 1 TRIM = 1 TRIMF(RIGID) = ALL $ SUBCASE 2 TRIM = 2 TRIMF(LOADSET=2) = ALL Subcase 1 will generate two load sets with set IDs 1 and 2. Subcase 2 will also output a load set ID 2. 4. The LOADSET option should not be specified in a TRIMF entry that is located above the subcase level. For example, consider the following:

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TRIMF(LOADSET=101) = ALL SUBCASE 1 TRIM = 1 SUBCASE 2 TRIM = 2 Here, both subcases will output trim loads with load set ID = 101.

Output The output of TRIMF are FORCE and MOMENT bulk data entries. The output is to either the punch file or defined file. See test case below for sample output.

Guidelines and Limitations The TRIMF request can be placed above all subcases, in which case it is in effect until overwritten or at the subcase level to make a subcase dependent request.

Test Cases The following test cases are available in the TPL in directory /tpl/ue6_09a: trimf.dat TPL file trimf.dat is a variation of the ha144e.dat test file documented in the MSC Nastran Aeroelastic ’s Guide. The variation is to add the following trimf commands in two of the five subcases: assign file='abrupt.inc', status=unknown,formatted,unit=53 ... ... SUBCASE 1 TRIM = 1 $ HIGH SPEED LEVEL FLIGHT SUBCASE 2 TRIM = 2 $ HIGH SPEED ROLLING PULLOUT SUBCASE 3 trimf(unit=53,loadset=1,rigid)=all TRIM = 3 $ HIGH SPEED PULLOUT WITH ABRUPT ROLL SUBCASE 4 trimf(loadset=10,inertia,air,rigid) = 100 TRIM = 4 $ HIGH SPEED SNAP-ROLL ENTRY SUBCASE 5 TRIM = 5 $ HIGH SPEED CLIMBING TURN

The test case in contrived to test a number of the features of the new capability. For example, the assign statement is used to capture the output from the third subcase while the data from the fourth subcase goes to the .pch file. It is seen that the output only goes to a set of grids in the fourth subcase. This feature could be used, for example, if only the loads on the wing are of interest.

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Subcase 3 output is to the defined file “abrupt.inc”$............................................................................... $ $ TRIM CASE: 3 $ RIGID (AERODYNAMIC + APPLIED - INERTIAL) LOADS $ FORCE 1 97 0 1.0 0.0 0.0 -14400. FORCE 1 98 0 1.0 0.0 0.0 6408.71 FORCE 1 99 0 1.0 0.0 -5.97767-16280.6 FORCE 1 100 0 1.0 0.0 -849.963-17073.7 FORCE 1 111 0 1.0 0.0 0.0 7102.12 FORCE 1 112 0 1.0 0.0 0.0 -9393.04 FORCE 1 121 0 1.0 0.0 0.0 35721.3 FORCE 1 122 0 1.0 0.0 0.0 -33645.6 FORCE 1 211 0 1.0 0.0 0.0 6736.25 FORCE 1 212 0 1.0 0.0 0.0 -2391.09 FORCE 1 221 0 1.0 0.0 0.0 -20757.3 FORCE 1 222 0 1.0 0.0 0.0 28125.5 FORCE 1 311 0 1.0 -1.84-11-832.2 -288. FORCE 1 312 0 1.0 -1.23-11 272.795-192. MOMENT 1 98 0 1.0 -645.697 0.0 0.0 MOMENT 1 99 0 1.0 -645.697 0.0 0.0 $............................................................................... $ $ TRIM CASE: 3 $ ELASTIC (AERODYNAMIC + APPLIED - INERTIAL) LOADS $ FORCE 2 97 0 1.0 0.0 0.0 -14400. FORCE 2 98 0 1.0 0.0 0.0 6958.1 FORCE 2 99 0 1.0 0.0 95.7669-14832.1 FORCE 2 100 0 1.0 0.0 -762.642-16588.3 FORCE 2 111 0 1.0 0.0 0.0 16858.9 FORCE 2 112 0 1.0 0.0 0.0 -10494. FORCE 2 121 0 1.0 0.0 0.0 46718.8 FORCE 2 122 0 1.0 0.0 0.0 -34359.8 FORCE 2 211 0 1.0 0.0 0.0 11975.7 FORCE 2 212 0 1.0 0.0 0.0 -2332.64 FORCE 2 221 0 1.0 0.0 0.0 -17538. FORCE 2 222 0 1.0 0.0 0.0 28513.3 FORCE 2 311 0 1.0 -1.84-11 526.924-288. FORCE 2 312 0 1.0 -1.23-11 139.951-192. MOMENT 2 98 0 1.0 -515.146 0.0 0.0 MOMENT 2 99 0 1.0 -515.146 0.0 0.0

Subcase 4 output goes to the default unit (punch file) $............................................................................... $ $ TRIM CASE: 4 $ RIGID INERTIAL LOADS $ FORCE 10 100 0 1.0 -1.65-12-33147.4-21.0849 FORCE 10 111 0 1.0 1584.39-4922.53-298.03 FORCE 10 112 0 1.0 1056.26-4337.95 954.982 FORCE 10 121 0 1.0 4753.18-3093.03 844.847 FORCE 10 122 0 1.0 3168.79-3118.28 1716.9 $............................................................................... $ $ TRIM CASE: 4 $ ELASTIC INERTIAL LOADS $ FORCE 11 100 0 1.0 -1.65-12-32947.6 44.9123 FORCE 11 111 0 1.0 1584.39-4922.53-369.264 FORCE 11 112 0 1.0 1056.26-4337.95 1861.03 FORCE 11 121 0 1.0 4753.18-3093.03 661.133 FORCE 11 122 0 1.0 3168.79-3118.28 1832.56

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$............................................................................... $ $ TRIM CASE: 4 $ RIGID AERODYNAMIC LOADS $ FORCE 12 100 0 1.0 0.0 416.853-16643.4 FORCE 12 111 0 1.0 0.0 0.0 9339.64 FORCE 12 112 0 1.0 0.0 0.0 -16832.9 FORCE 12 121 0 1.0 0.0 0.0 18282.9 FORCE 12 122 0 1.0 0.0 0.0 -4692.2 $............................................................................... $ $ TRIM CASE: 4 $ ELASTIC AERODYNAMIC LOADS $ FORCE 13 100 0 1.0 0.0 166.317-15698.5 FORCE 13 111 0 1.0 0.0 0.0 24597.3 FORCE 13 112 0 1.0 0.0 0.0 -19263.1 FORCE 13 121 0 1.0 0.0 0.0 33389. FORCE 13 122 0 1.0 0.0 0.0 -5317.57 $............................................................................... $ $ TRIM CASE: 4 $ RIGID (AERODYNAMIC + APPLIED - INERTIAL) LOADS $ FORCE 14 100 0 1.0 -1.65-12-32730.5-16664.5 FORCE 14 111 0 1.0 1584.39-4922.53 9041.61 FORCE 14 112 0 1.0 1056.26-4337.95-15877.9 FORCE 14 121 0 1.0 4753.18-3093.03 19127.7 FORCE 14 122 0 1.0 3168.79-3118.28-2975.3 $............................................................................... $ $ TRIM CASE: 4 $ ELASTIC (AERODYNAMIC + APPLIED - INERTIAL) LOADS $ FORCE 15 100 0 1.0 -1.65-12-32781.3-15653.6 FORCE 15 111 0 1.0 1584.39-4922.53 24228.1 FORCE 15 112 0 1.0 1056.26-4337.95-17402.1 FORCE 15 121 0 1.0 4753.18-3093.03 34050.1 FORCE 15 122 0 1.0 3168.79-3118.28-3485.

GUI Patran currently does not the TRIMF case control SimXpert does not have an aeroelastic workspace.

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CSV Output of Trim Results Introduction MSC Nastran 2010 contains a new feature that allows the to create a summary of the trim results in a CSV (Comma Separated Values) file suitable for viewing and manipulating in a spreadsheet application.

Benefits The CSV file provides a convenient summary of the trim results that would otherwise have to be gleaned from disparate parts of the .f06 file. This is particularly valuable when hundreds of subcases are being analyzed in a single run.

Input The CSV feature in activated by PARAM LDSUM (Ch. 5) in the MD/MSC Nastran Quick Reference Guide. The unit the CSV file is written to is specified by PARAM XYUNIT. An assign statement such as: assign file='aecsv1.csv' status=unknown form=formatted unit=52 defines the file where the results are stored. The unit 52 corresponds to PARAM XYUNIT 52.

PARAM LDSUM Default = 0 Dictates what information is to be stored on a CSV (comma separated values) file in a SOL 144 (static aeroelasticity) task. The unit the CSV file is stored to is specified by param XYUNIT. LDSUM has the following options: • = 0 (Default) – Do not create a CSV file for static aeroelasticity • =1 Create a CSV file that contains for each static aeroelastic subcase:

a. Subcase ID b. Mach number c. Dynamic Pressure d. Trim Values e. Mass and CG information (mass, xcg,ycg,zcg, IXX,IYY,IZZ,IXY,IXZ and IYZ) • =2

Same as 1 plus net structural monitor point (MONPNT1, MONDPS1, MONPNT2, MONPNT3) results

• = 3 Same as 2 plus the output of RIGID AIR, ELASTIC RESTRAINED, and INERTIAL,

RIGID APPLIED and ELASTIC APPLIED components for the structural MONPNT1 results

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Output The output is a csv file as shown in the test case below.

Guidelines and Limitations 1. PARAM LDSUM can appear in case control or in the bulk data portion of the input file. Only one PARAM LDSUM can appear. 2. The first row in the spreadsheet provides titles for the columns that contain the results. Each subsequent row contains all the requested results for a single subcase. This means that there is a potential for more columns in the row than standard spreadsheet programs like Microsoft Excel can accommodate. This implies it may be necessary to use a special purpose spreadsheet tool to take full advantage of the new capability. 3. The PARAM XYUNIT is also used in SOL 200 to provide design optimization results. If the SOL 200 run includes static aeroelastic subcases and PARAM LDSUM is used, the resulting spreadsheet will have a row for each static aero subcase for each design iteration followed by the design optimization results.

Test Cases The following test cases are available in the TPL in directory /tpl/ue_csv09: aecsv1.dat, aecsv4.dat TPL Problem aecsv1.dat TPL example problem aecsv1 uses PARAM,LDSUM,1 to provide a summary of the trim results without any monitor points results. assign file='OUTDIR:aecsv1.csv' status=unknown, form=formatted unit=52 SOL 144 $ STATIC AERO CEND param ldsum 1 $ control for csv output param xyunit 52 $ output unit for csv file TITLE = EXAMPLE HA144F: FSW WITH FUSELAGE, 3 CONTROLS & 2 STOR HA144F SUBTI = UNSYMMETRIC FLIGHT CONDITIONS, DOUBLET-LATTICE AERO LABEL = FULL-SPAN MODEL WITH DISPLACED CANARD ECHO = BOTH SPC = 1 $ SYMMETRIC CONSTRAINTS MPC = 10 $ CANARD/FUSELAGE STRUCTURAL CONNECTIONS DISP = ALL $ PRINT ALL DISPLACEMENTS MONITOR = ALL SUBCASE 1 TRIM = 1 $ HIGH SPEED LEVEL FLIGHT BEGIN BULK

Partial listing of the resulting CSV file: Sub Case,Mach,Dynamic Pressure ,INTERCEPT ,ANGLEA ,P ... 1, 9.000000E-01, 1.200000E+03, 1.000000E+00 ...

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TPL Problem aecsv4.dat TPL problem aecsv4.dat is a more comprehensive example geometry with PARAM,LDSUM,4 to provide a summary of the trim results including comprehensive monitor point results.

Figure 6-4

TPL Problem aecsv4.dat

assign file='OUTDIR:aecsv4.csv' status=unknown, form=formatted unit=52 SOL 144 TIME 600 END param ldsum 4 $ control for csv output param xyunit 52 $ output unit for csv file SEALL = ALL SUPER = ALL ECHO = SORT MAXLINES = 999999 AECONFIG = Freedom4 SUBCASE 1 $ Subcase name : Mach .4 Level Flight SUBTITLE=Mach .4 Level Flight DISPLACEMENT(SORT1,REAL,plot)=ALL SPCFORCES(SORT1,REAL)=ALL OLOAD(SORT1,REAL,plot)=ALL STRESS(SORT1,REAL,VONMISES,BILIN,plot)=ALL TRIM = 1 AESYMXZ = Asymmetric AESYMXY = Asymmetric 1 = 1 AEROF = ALL APRES = ALL BEGIN BULK PARAMAESMETHRITZ

GUI Patran currently does not PARAM,LDSUM SimXpert does not have an aeroelastic workspace.

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SUBCOM/SUBSEQ with Static Aeroelasticity Introduction The SUBCOM/SUBSEQ commands that were previously limited to statics problems have been extended to static aeroelasticity problems (both in SOL 144 and in SOL 200 with ANALYSIS=SAERO).

Benefits The motivation for this task is to allow a scaling of the results (displacements and element responses) from a static aeroelastic trim analysis as a postprocessing operation. This is particularly of benefit in an optimization task where one desires to explore applying different limit factors to the results in a design task.

Inputs The existing SUBCOM/SUBSEQ case control commands have been activated for a static aeroelastic analysis. Typically, a single SUBSEQ coefficient is used to scale the results of the previous subcase, although multiple coefficients are ed. In a SOL 200 job, the SUBCOM subcase needs to be accompanied by an ANALYSIS=SAERO command to designate that this subcase is to be grouped with the static aeroelastic subcases.

Outputs Data recovery occurs for the SUBCOM subcases in the same way as any other subcase. The SUBCOM ID appears on the right hand side of the page to indicate that the results are associated with the SUBCOM

Guidelines and Limitations Only element and grid responses are affected by the SUBCOM. Trim results and stability derivative results are neither computed or output. In SOL 200, it is illegal to invoke a DRESP1 with RTYPE = STABDER or TRIM from a SUBCOM subcase that has ANALYSIS=SAERO.

Example A variation of the familiar HA144A test case for the forward swept wing is used to demonstrate the new SUBCOM capability in a SOL 144 test case. The test case is available in the TPL in directory /tpl/ue_csv09: subcoma.dat. The case control is shown below and it is seen that there is a SUBCOM 4 that requests output that is 50% greater than that of subcase 3. TITLE = EXAMPLE HA144A: 30 DEG FWD SWEPT WING WITH CANARD HA14 HA144A SUBTI = SYMMETRIC FLIGHT CONDITIONS, DOUBLET-LATTICE AERO LABEL = HALF-SPAN MODEL, STATIC SYMMETRIC LOADING

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ECHO = BOTH SPC = 1 $ DISP = ALL $ STRESS = ALL $ FORCE = ALL $ AEROF = ALL $ APRES = ALL $ SUBCASE 1 TRIM = 1 $ SUBCASE 2 TRIM = 2 $ SUBCASE 3 TRIM = 3 $ subcom 4 subseq(1.5) BEGIN BULK

SYMMETRIC PRINT ALL PRINT ALL PRINT ALL PRINT ALL PRINT ALL

CONSTRAINTS DISPLACEMENTS STRESSES FORCES AERODYNAMIC FORCES AERODYNAMIC PRESSURES

1 G LEVEL FLIGHT (LOW SPEED) 1 G LEVEL FLIGHT (HIGH SUBSONIC SPEED) 1 G LEVEL FLIGHT (LOW SUPERSONIC SPEED)

A snippet of the output from this job is shown below. It is seen that the displacements of SUBCOM 4 are 50% greater than those of SUBCASE 3.

1 0

EXAMPLE HA144A: 30 DEG FWD SWEPT WING WITH CANARD HA14 HA144A SYMMETRIC FLIGHT CONDITIONS, DOUBLET-LATTICE AERO HALF-SPAN MODEL, STATIC SYMMETRIC LOADING D I S P L A C E M E N T

1 0

POINT ID. TYPE T1 T2 T3 90 G 0.0 0.0 0.0 97 G 0.0 0.0 -5.984770E-03 98 G 0.0 0.0 -8.086921E-04 99 G 0.0 0.0 -8.673837E-04 100 G 0.0 0.0 -9.000074E-03 110 G 0.0 0.0 -2.312949E-03 111 G 0.0 0.0 2.641245E-03 112 G 0.0 0.0 -7.267144E-03 120 G 0.0 0.0 1.953165E-02 121 G 0.0 0.0 2.512188E-02 122 G 0.0 0.0 1.394143E-02 EXAMPLE HA144A: 30 DEG FWD SWEPT WING WITH CANARD HA14 HA144A SYMMETRIC FLIGHT CONDITIONS, DOUBLET-LATTICE AERO HALF-SPAN MODEL, STATIC SYMMETRIC LOADING D I S P L A C E M E N T POINT ID. 90 97 98 99 100 110 111 112 120 121 122

Main Index

TYPE G G G G G G G G G G G

0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

T1

0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

T2

T3

0.0 -8.977155E-03 -1.213038E-03 -1.301076E-03 -1.350011E-02 -3.469424E-03 3.961868E-03 -1.090072E-02 2.929747E-02 3.768281E-02 2.091214E-02

OCTOBER

21, 2009

MSC Nastran

10/20/09

PAGE

62

PAGE

63

SUBCASE 3 V E C T O R R1 R2 0.0 0.0 0.0 0.0 -6.176078E-04 0.0 0.0 -3.176077E-04 0.0 0.0 3.528226E-04 0.0 0.0 1.363732E-03 0.0 6.497581E-04 1.981678E-03 0.0 6.497581E-04 1.981678E-03 0.0 6.497581E-04 1.981678E-03 0.0 1.088872E-03 2.236090E-03 0.0 1.088872E-03 2.236090E-03 0.0 1.088872E-03 2.236090E-03 0.0 OCTOBER 21, 2009 MSC Nastran

R3

10/20/09 SUBCOM 4

V E C T O R R1 0.0 0.0 0.0 0.0 0.0 9.746371E-04 9.746371E-04 9.746371E-04 1.633308E-03 1.633308E-03 1.633308E-03

R2 0.0 -9.264118E-04 -4.764115E-04 5.292339E-04 2.045598E-03 2.972517E-03 2.972517E-03 2.972517E-03 3.354135E-03 3.354135E-03 3.354135E-03

0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

R3


Upper Hessenberg Complex Eigenanalysis No Longer ed for Flutter Analysis The original implementation of the PK flutter analysis utilized an Upper Hessenberg algorithm for extracting complex eigenvalues. In MSC Nastran 2005 R3, a QZ algorithm was introduced that had the advantage of being able to accommodate a singular matrix. For several releases, the Upper Hessenberg algorithm could still have been used if NASTRAN SYSTEM(108)=1 was specified. This option is no longer available and the use of SYSTEM(108)=1 will cause a Information Message to be printed:

*** INFORMATION MESSAGE 5282 (FA1PKE) SYSTEM(108) HAS A NONZERO VALUE, IMPLYING THERE IS A preference TO USE THE UPPER HESSENBERG METHOD FOR PK FLUTTER ANALYSIS. information: THIS IS NO LONGER ED AND THE DEFAULT QZ ALGORITHM WILL BE USED.

Main Index


Main Index

Chapter 7: Elements MSC Nastran Release Guide

7

Main Index

Elements



Enhancements to Connector Elements



Offsets for Beams and Shells

114 MSC Nastran 2010 Release Guide Enhancements to Connector Elements

Enhancements to Connector Elements Introduction A finite element modeler has many ways of modeling structural connections and fasteners. Spot welds, seam welds, bolts, screws, and so on can be represented, depending on the modeling goals, either with flexible springs or bars (CBUSH, CBAR), rigid elements (RBAR, RBE2, RBE3), or multipoint constraints (MPC). Though generally, these elements are sometimes difficult to use; singularities may be introduced particularly in the out-of-plane rotational direction for shells, rigid body invariance may not be assured, and data preparation and input can be a formidable task in real-world applications. Increasing mesh refinement can also introduce further stiffness errors; point-to-point connections in which effective cross-sectional areas are larger than 20% of the characteristic element lengths can often lead to significant underestimation of connector stiffness. Connector elements are a special class of elements that were introduced to MSC Nastran in V2001. The first implementation was for elements that represent spot welds. These elements are convenient to define by the because all that is necessary to define the elements a geometric location in space. Subsequent versions of MSC Nastran have provided many enhancements and now include elements that can model bolts and seam welds. In MSC Nastran 2010, there have been further enhancements to the existing elements to allow data recovery in dynamic solution sequences, calculate displacements and stresses for seam weld elements and defined coordinate systems for spot weld elements the way that defined coordinate systems are used for bolt elements.

Benefits The following features are included in MSC Nastran 2010. 1. auxiliary displacement output for frequency response and transient analysis for CWELD, CFAST and CSEAM elements. 2. Generate eight auxiliary grids internally and compute their associated displacements for CSEAM elements. 3. Provide stress and strain output for CSEAM elements. 4. defined element coordinate system for CWELD elements.

Theory Mathematical Model to Construct the CSEAM Auxiliary Points The four auxiliary vertex points of the cross section at start point GS are constructed by the following s

s

equations (see Figure 7-1), where t 1 and t 2 are tangent vectors of the element coordinate system at start

Main Index

CHAPTER 7 115 Elements

s

point GS, W is the width of the seam, and T is the thickness of the seam. For a continuous seam, t 1 and s

t 2 vectors are adjusted to a common face for the two consecutive seam elements. Therefore, the four auxiliary grids at the start point S of the ith seam should be coincident with the four auxiliary grids at the end point E of the (i-1)th seam, if both elements have same width and thickness. W s T s x S A1 = x s – ----- t 1 – --- t 2 2 2 W s T s x S A2 = x s – ----- t 1 – --- t 2 2 2 W s T s x S B1 = x s – ----- t 1 – --- t 2 2 2 W s T s x S B2 = x s – ----- t 1 – --- t 2 2 2 s

t2 GSB1

GSB2

T/2 s

GS

T/2

t1

GSA1

GSA2 W/2

Figure 7-1

W/2

Seam Weld Cross Section at Start Point S

The four auxiliary vertex points of the cross section at end point GE are calculated in the same way as that for the start point GS. These eight auxiliary points form an auxiliary HEXA element with the following vertex points.

Main Index

1

2

3

4

5

6

7

8

GSA1

GSA2

GSB2

GSB1

GEA1

GEA2

GEB2

GEB1


Input The only new input is related to the element coordinate system on the CWELD entry. The relevant changes are shown in the following CWELD entry (other items that did not change are not shown). The other enhancements are to extend the solution sequences and provide additional output for the CSEAM.

Main Index


CWELD

Weld or Fastener Element Connection

Defines a weld or fastener connecting two surface patches or points. Large displacement and large rotational effects are ed when using SOL 600 and MSC Nastran SOL 400 only. Format: 1

2

3

4

5

6

7

CWELD

EWID

PWID

GS

“PARTPAT”

8

9

GA

GB

MCID

PIDA

PIDB

XS

YS

ZS

101

8

203

21

33

GA

GB

MCID

GA

GB

MCID

GA

GB

Example: CWELD

PARTPAT

Alternate formats and examples: Format ELPAT: CWELD

EWID

PWID

GS

“ELPAT”

SHIDA

SHIDB

XS

YS

ZS

103

5

403

ELPAT

309

511

GS

“ELEMID”

403

ELEMID

GS

“GRIDID”

Example: CWELD

Format ELEMID: CWELD

EWID

PWID

SHIDA

SHIDB

103

5

309

511

Example: CWELD

Format GRIDID: CWELD

Main Index

EWID

PWID

SPTYP

MCID

10


GA1

GA2

GA3

GA4

GA5

GA6

GA7

GA8

GB1

GB2

GB3

GB4

GB5

GB6

GB7

GB8

7

29

233

GRIDID

15

28

31

35

46

51

3

5

8

Example: CWELD

QT 55

60

Format ALIGN: CWELD

EWID

PWID

“ALIGN”

GA

GB

7

29

ALIGN

103

259

MCID

Example: CWELD

Field

Contents

Type

Default

MCID

Specifies the element stiffness coordinate system. See Remark 15.

Integer > -1 or Default = -1 blank

Remarks: 15. MCID = -1 or blank (Default), then the coordinate system is as defined in Remark 12. If MCID > 0, then a “beam” like coordinate system is defined. The x ele m axis direction of the connector defined as 1

xB – xA = --------------------xB – xA

Output The results of CWELD and CFAST elements are stored in standard beam and standard bush formats respectively; while the results of CSEAM elements are displayed in hexa format with the eight auxiliary grids as vertex points. For frequency response, the output data may be in rectangular or polar format. The examples below will give a description of the output.

Test Cases The following test cases are available in the TPL in directory /tpl/rg4_conn: r4_conn_exa.dat, r4_conn_exb.dat

Main Index


TPL example model r4_conn_exa.dat This example demonstrates the modeling of frequency response for CWELD elements with defined element coordinate system and the ELPAT format:

Figure 7-2

Example r4_conn_exa.dat geometry

SOL 108 END DISPL= ALL FORCE=1 STRESS=1 SUBCASE 1 SUBTITLE= shear the weld dload=1 method= 400 freq=11 BEGIN BULK $ Spot weld cweld, 30, 30, 300, elpat, , , , 755, +CW1 +CW1, 11, 10 pweld, 30, 10, 0.1 $ cord2r, 755, , 0., 0., 0., 0., 0., -1., , 0., 1., 0.

Note:

Main Index

Turning on additional diagnostics with SWLDPRM,PRTSW,1 will provide information about the auxiliary GRID locations and ids. The displacement printout shown afterwards gives the auxiliary GRID displacements.


CWELD EID= 30 WITH ELPAT OR PARTPAT GS IS MOVED FROM ( 1.0000E+00, 4.0000E-01, 5.0000E-01) TO ( 1.0072E+00, 3.9841E-01, 2.3848E-01) AUXILIARY POINTS= ( 9.8328E-01, 3.6349E-01, 4.3080E-01) ( 1.0718E+00, 3.6307E-01, 4.2595E-01) ( 1.0714E+00, 4.5062E-01, 4.1219E-01) ( 9.8294E-01, 4.5104E-01, 4.1704E-01) ( 9.7227E-01, 3.5413E-01, 4.8613E-02) ( 1.0608E+00, 3.5407E-01, 5.3039E-02) ( 1.0608E+00, 4.4269E-01, 5.3042E-02) ( 9.7233E-01, 4.4275E-01, 4.8616E-02) NUMBER OF TIMES GS MOVES= 1 NUMBER OF TIMES DA IS REDUCED= 0 ANGLE BETWEEN TWO SHELL NORMALS= 10.77 GS=( 1.007E+00, 3.984E-01, 2.385E-01) GA=( 1.027E+00, 4.071E-01, 4.215E-01) GB=( 1.017E+00, 3.984E-01, 5.083E-02) T_BE MATRIX: -2.9113E-02 9.9958E-01 0.0000E+00 -2.3310E-02 -6.7890E-04 -9.9973E-01 -9.9930E-01 -2.9105E-02 2.3320E-02 GA ID = 101000001 GB ID = 101000002 PATCH A: EID= 11 GIDS= 111 112 113 114 0 0 0 0 EID= 11 GIDS= 111 112 113 114 0 0 0 0 EID= 11 GIDS= 111 112 113 114 0 0 0 0 EID= 11 GIDS= 111 112 113 114 0 0 0 0 PATCH B: EID= 10 GIDS= 101 102 104 0 0 0 0 0 EID= 10 GIDS= 101 102 104 0 0 0 0 0 EID= 10 GIDS= 101 102 104 0 0 0 0 0 EID= 10 GIDS= 101 102 104 0 0 0 0 0

The displacement, element force and stress results are shown as follows.

0

0

FREQUENCY =

POINT ID. 101

1.000000E+01

TYPE G

0

102

G

0

104

G

0

111

G

0

112

G

0

113

G

0

114

G

0

300

G

0

101000001

G

0

101000002

G

0

Main Index

SUBCASE 1 C O M P L E X

T1 -7.791607E+00 5.248972E-07 -7.795311E+00 -3.276013E-06 -8.547235E+00 1.220098E-05 -7.810302E+00 2.649062E-06 -7.806551E+00 8.092410E-07 -8.705634E+00 -8.982315E-06 -8.569546E+00 1.027111E-07 0.0 0.0 -8.114884E+00 -7.519017E-07 -8.094540E+00 3.244864E-06

T2 -6.924270E-01 1.286137E-05 8.285373E-01 -1.135917E-05 -6.924270E-01 1.286628E-05 -6.437430E-01 -7.254856E-06 7.064308E-01 1.905125E-06 8.381162E-01 3.584831E-06 -6.340333E-01 -8.022997E-06 0.0 0.0 1.247901E-01 -2.020528E-06 8.064318E-02 5.525994E-07

D I S P L A C E M E N T (REAL/IMAGINARY) T3 1.487187E-02 -3.858250E-05 8.895068E-02 3.686814E-05 -8.223225E-02 -3.003202E-05 1.438998E-02 1.925463E-05 8.188874E-02 -1.219865E-05 -2.708165E-02 -1.199635E-05 -8.270818E-02 2.709107E-05 0.0 0.0 1.340001E-02 3.345231E-06 1.383702E-02 3.173882E-06

V E C T O R

R1 -9.710412E-02 8.550648E-06 -9.710412E-02 8.550648E-06 -9.710412E-02 8.550648E-06 -9.709817E-02 7.837443E-06 -9.706381E-02 3.714137E-06 -9.705853E-02 3.080924E-06 -9.709751E-02 7.757903E-06 0.0 0.0 -9.707516E-02 5.076566E-06 -9.710412E-02 8.550648E-06

R2 -3.703940E-02 -3.772603E-05 -3.703940E-02 -3.772603E-05 -3.703940E-02 -3.772603E-05 -3.749770E-02 1.728056E-05 -3.750144E-02 1.772999E-05 -3.752504E-02 2.056146E-05 -3.751689E-02 1.958415E-05 0.0 0.0 -3.750778E-02 1.849139E-05 -3.703940E-02 -3.772603E-05

R3 7.556269E-01 -1.167940E-05 7.556269E-01 -1.167940E-05 7.556269E-01 -1.167940E-05 7.554925E-01 4.460259E-06 7.554878E-01 5.025620E-06 7.554884E-01 4.950366E-06 7.554936E-01 4.324563E-06 0.0 0.0 7.554896E-01 4.807756E-06 7.556269E-01 -1.167940E-05 SUBCASE 1


0

02

FREQUENCY =

ELEMENT ID 30

SUBCASE 1 F O R C E S

FREQUENCY =

ELEMENT ID 30

I N W E L D E L E M E N T S (REAL/IMAGINARY)

( C W E L D P )

BEND-MOMENT END-A BEND-MOMENT END-B - SHEAR PLANE 1 (MZ) PLANE 2 (MY) PLANE 1 (MZ) PLANE 2 (MY) PLANE 1 (FY) PLANE 2 (FZ) -1.196586E-01 5.743172E-03 -3.431428E-03 3.061221E-03 -3.133458E-01 7.230475E-03 1.436048E-02 -6.890686E-04

03 0

1.000000E+01 C O M P L E X

1.000000E+01 C O M P L E X

AXIAL STRESS 1.147757E+00 -1.376786E-01

4.131643E-04 -3.671607E-04

3.760163E-02 -8.678561E-04

AXIAL FORCE FX 9.014460E-03

TORQUE MX -1.499722E-

-1.081325E-03

1.800308E-

SUBCASE 1 S T R E S S E S

MAX STRESS END-A 1.278480E+03 1.531557E+02


MIN STRESS END-A -1.276184E+03 -1.534311E+02

MAX STRESS END-B 6.728133E+01 7.810646E+00

( C W E L D P )

MIN STRESS END-B -6.498582E+01 -8.086003E+00

MAXIMUM BEARING SHEAR STRESS STRESS 1.297688E+02 3.134292E+01 1.557555E+01 3.761164E+00

TPL Problem r4_conn_exb.dat TPL problem r4_conn_exb.dat demonstrates the static analysis for CSEAM elements with displacement and stress output requests. In this case there are several overlapping plates connected with CSEAM. The CSEAM model has internally generated auxiliary grid IDs starting from 90001.

Figure 7-3

Example r4_conn_exb.dat geometry

sol 101 cend load = 10 spc = 10 disp = all set 4 = 10001,10002,10003,10004,10005 stress = 4 begin bulk ... swldprm prtsw 1 $ cseam100011000se0elem113214 1000110002 cseam100021000se010elem330440 1000310004 cseam100031000se1010elem5030060400 1000510006

Main Index


cseam100041000sl1030pshell70200 1000710008 cseam100051000sl1030 pshell70200 1000910010 $ $23456 pseam 1000 200.2 $

The displacement and stress results are shown as follows.

0 D I S P L A C E M E N T POINT ID. 509 10001 10002 10003 10004 10005 10006 10007 10008 10009 10010 101000001 101000002 101000003 101000004 101000005 101000006 101000007 101000008 101000009 101000010 101000011 101000012 101000013 101000014

TYPE G G G G G G G G G G G G G G G G G G G G G G G G G

T1 2.805908E-02 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 7.372772E-03 7.673701E-03 6.849292E-03 6.850486E-03 7.376085E-03 7.677149E-03 6.851723E-03 6.853319E-03 2.237370E-02 2.267277E-02 2.469706E-02 2.469634E-02 2.237715E-02 2.267609E-02

T2 -2.599996E-04 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 3.151977E-03 3.151946E-03 -2.230086E-04 -2.224528E-04 -3.603303E-03 -3.603285E-03 -2.002655E-04 -2.007576E-04 3.150388E-03 3.150356E-03 -2.220506E-04 -2.216082E-04 -3.602424E-03 -3.602407E-03

T3 -2.023823E-01 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 -3.154194E-02 -3.261929E-02 -3.259117E-02 -3.151381E-02 -2.985591E-02 -3.093446E-02 -3.090637E-02 -2.982783E-02 -1.297074E-01 -1.325928E-01 -1.326306E-01 -1.297368E-01 -1.284061E-01 -1.313060E-01

V E C T O R R1 6.784551E-05 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

R2 1.449939E-02 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

R3 -6.875442E-07 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

0 0

ELEMENT-ID 0 10001 0 0 0 0 0 0 0 0 0

Main Index

CORNER GRID-ID 0GRID CENTER X Y Z 101000001 X Y Z 101000002 X Y Z 101000003 X Y Z 101000004 X Y Z 101000005 X Y Z 101000006 X Y Z 101000007 X Y Z 101000008 X Y Z

S T R E S S E S I N S E A M E L E M E N T S ( C S E A M ) ------CENTER AND CORNER POINT STRESSES--------DIR. COSINES NORMAL SHEAR PRINCIPAL -A- -B- -CCS 8 GP 7.490945E+02 XY 3.996807E-02 A 7.490945E+02 LX 1.00 0.0 0.0 2.938447E-01 YZ -7.958079E-13 B 1.469501E-01 LY 0.00 0.0 0.0 0.0 ZX 9.094947E-12 C 1.469501E-01 LZ 0.00 0.0 0.0 1.635867E+03 XY 7.365383E-02 A 1.635867E+03 LX 1.00 0.00 0.00 1.320214E+02 YZ -2.318950E-02 B 1.320214E+02 LY 0.00 1.00 0.00 3.053776E+02 ZX -3.091930E-04 C 3.053776E+02 LZ 0.00 0.00-1.00 1.635903E+03 XY 7.365383E-02 A 1.635903E+03 LX 1.00 0.00 0.00 1.320599E+02 YZ 2.318950E-02 B 1.320599E+02 LY 0.00 1.00 0.00 3.054590E+02 ZX -3.091930E-04 C 3.054590E+02 LZ 0.00 0.00-1.00 -1.369259E+02 XY 6.282309E-03 A -1.311691E+02 LX 0.00 0.00-1.00 -1.311691E+02 YZ 2.318950E-02 B -3.053584E+02 LY 1.00 0.00 0.00 -3.053584E+02 ZX -3.091930E-04 C -1.369259E+02 LZ 0.00 1.00 0.00 -1.370004E+02 XY 6.282309E-03 A -1.312972E+02 LX 0.00 0.00-1.00 -1.312972E+02 YZ -2.318950E-02 B -3.054782E+02 LY 1.00 0.00 0.00 -3.054782E+02 ZX -3.091930E-04 C -1.370004E+02 LZ 0.00 1.00 0.00 1.636985E+03 XY 7.365383E-02 A 1.636985E+03 LX 1.00 0.00 0.00 1.326195E+02 YZ -2.318950E-02 B 1.326195E+02 LY 0.00 1.00 0.00 3.062530E+02 ZX 3.091930E-04 C 3.062530E+02 LZ 0.00 0.00-1.00 1.636935E+03 XY 7.365383E-02 A 1.636935E+03 LX 1.00 0.00 0.00 1.325717E+02 YZ 2.318950E-02 B 1.325717E+02 LY 0.00 1.00 0.00 3.061331E+02 ZX 3.091930E-04 C 3.061331E+02 LZ 0.00 0.00-1.00 -1.395096E+02 XY 6.282309E-03 A -1.322068E+02 LX 0.00 0.00-1.00 -1.322068E+02 YZ 2.318950E-02 B -3.062338E+02 LY 1.00 0.00 0.00 -3.062338E+02 ZX 3.091930E-04 C -1.395096E+02 LZ 0.00 1.00 0.00 -1.394977E+02 XY 6.282309E-03 A -1.322486E+02 LX 0.00 0.00-1.00 -1.322487E+02 YZ -2.318950E-02 B -3.061523E+02 LY 1.00 0.00 0.00 -3.061523E+02 ZX 3.091930E-04 C -1.394977E+02 LZ 0.00 1.00 0.00

MEAN PRESSURE

VON MISES

-2.497961E+02

7.489476E+02

-6.910887E+02

1.425098E+03

-6.911407E+02

1.425078E+03

1.911511E+02

1.713834E+02

1.912586E+02

1.714006E+02

-6.919526E+02

1.425502E+03

-6.918799E+02

1.425529E+03

1.926500E+02

1.704930E+02

1.926329E+02

1.703949E+02


Offsets for Beams and Shells Introduction The original design of the BAR, BEAM and shells included an offset feature. This feature allows you to specify a BAR/BEAM axis of shear centers offset from connected grid points; and, a shell element reference plane offset from the connected grids for triangular and quadrilateral shell elements. The axis of the elastic BAR/BEAM was assumed to extend from the two endpoints offset from the connected grid points; and, the reference surface of the shell element connected points offset from the connected grids. The elastic stiffness was then calculated in the offset element coordinate system and transformed to the connected grid points using the rigid body transformation equations.

Figure 7-4

CBAR and CBEAM Element Offset Definitions

Figure 7-5

CQUAD4 and CQUAD8 Element Coordinate System Definitions

Prior to the offset project in MSC Nastran 2010, element offsets had the following limitations: • The differential stiffness is not ed. Therefore, they are not applicable in solution

sequence where differential stiffness is required, such as linear buckling analysis (SOL 105). • The effect of offsets is not included the mass matrix, thus in dynamic analysis, the mass matrix

is only an approximation for offsets.

Main Index

124 MSC Nastran 2010 Release Guide Offsets for Beams and Shells

• The effect of offset is not included in computation of thermal loads, pressure loads, or gravity

loads. • For curved shell problems, the offset is defined in the z direction of the element and not the shell

normal direction, this results in gaps between elements when offset geometry is applied. • The transformation is linear; therefore, it cannot be used nonlinear analysis.

This enhancement extends the use the offsets to nonlinear solutions, linear differential stiffness, load and mass generation and maintenance of geometric continuity for adjacent curved shells along the common shell normal. Note:

The element offset project was completed for both MD Nastran and MSC Nastran. This section includes the complete capability description for both MD Nastran and MSC Nastran as documented in the MD Nastran 2010 Release Guide. For MSC Nastran, the new offset methods are available in all the linear solution sequences that calculate differential stiffness, but the new offset capability is not available in the MSC Nastran nonlinear solutions (SOL 106 and SOL 129).

Benefit The enhanced offset method has the following benefits: • DIFFERENTIAL STIFFNESS - The differential stiffness is computed for the offset so that it is

applicable to solution sequences that required differential stiffness. These include, for example, SOL 103, SOL 105, and SOL 400. • MASS - The effect of offset is included in the mass matrix generation. • LOADS - The effect of offset is included in the load generation. • GEOMETRY COMPATIBILITY - For QUAD4, TRIA3, QUADR, TRIAR, QUAD8 and

TRIA6 elements the shell normal is used as the offset direction. Thus, the new offset will enhance solution of a model in two aspects: there is no gap in the offset geometry, and the mass and stiffness matrices are computed based on the offset geometry. Figures New Offset Behavior when Angle between adjacent elements is less than SNORM and New Offset Behavior when Angle between adjacent elements is greater than SNORM demonstrate how the new offsets are considered in conjunction with SNORM. • NONLINEAR EFFECTS - The transformations are nonlinear so that it can be used in

nonlinear analysis such as SOL 400.

Feature Description Differential Stiffness The original offset method does not compute the differential stiffness for offset. Therefore, it is not applicable to solution sequences where differential stiffness is needed such as SOL 103 or SOL 105. The

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enhanced offset computes the differential stiffness for offset, using the same formulation as that of the Lagrange RBAR element. The Lagrange multipliers are eliminated internally. For the new offset method, the differential stiffness is computed for offsets for solution sequences that require it. These include SOL 105, SOL 400 and any linear solution that s differential stiffness effects via the case control entry STATSUB. Mass Matrix For an element, the mass matrix is computed at the offset locations of the element. The mass matrix needs to be transformed from the offset locations to the external grid points. In performing this transformation, mass moments of inertial are created. Without this transformation, the mass matrix for model with offsets is only an approximation. With this transformation, the mass matrix for SOL 103, and other dynamic solution sequences are correctly computed. The additional in the mass matrix may adversely affect the solution time for dynamic solutions; therefore, a provision to disable the mass offset calculation while retaining other offset effects is available. Load Effects For element loads, such as thermal, pressure, and gravity load, the loads are computed at the offset locations of the element. These loads are transformed from the offset locations to the external grid points. For thermal load, there are two types of effect due to offset: • The location of thermal load is changed due to offset, i.e. the thermal load is first computed at

the element offset locations and then transformed to the external grid points. This effect is computed for both linear solution sequences and nonlinear solution sequence SOL 400. • The temperature load will change the length of the offset. This effect is computed for the

nonlinear solution sequence SOL 400 only. If you don’t want these effects to be calculated, a provision to disable the offset load effects is available. Offset Direction For beam elements, the direction of offset is given by the WiA and WiB on the connection Bulk Data entries. For shell elements, the old offset direction is in z-direction of the element coordinate system. For curved shell model, such as cylindrical shell, this approach has two deficiencies: • The offset geometry has gap or overlap in the structure model. • The computations of stiffness matrix, mass matrix, and element load are based on the original

geometry, which is not the same as the offset geometry. In order to remedy these deficiencies, the new offset method for QUAD4, TRIA3, QUADR, TRIAR, QUAD8, and TRIA6 use the shell normal as the offset direction for default.

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If you don’t want the geometric advantages of the new offset method, a provision to revert to the previous offset behavior for shell elements is available.

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Figure 7-6

Unique Grid Point Normal for Adjacent Shell Elements

Figure 7-7

New Offset Behavior when Angle between adjacent elements is less than SNORM

Figure 7-8

New Offset Behavior when Angle between adjacent elements is greater than SNORM


Nonlinear Analysis For nonlinear analysis, the following are implemented for the new offset method: • The offsets are formulated in large rotation theory. • The differential stiffness for offsets is computed. • For thermal loads, the length of the offsets may change due to thermal loads. This effect has

been implemented.

Input The new offset formulation must be invoked by specifying MDLPRM,OFFDEF,option in the Bulk Data Section. The format of the MDLPRM entry and options associated with OFFDEF are shown. MDLPRM Format: 1

2

3

4

5

6

7

8

MDLPRM

PARAM1

VAL1

PARAM2

VAL2

PARAM3

VAL3

-etc.-

QR6ROT

2

QRSHEAR

1

OFFDEFF

LROFF

9

10

Example: MDLPRM

Name OFFDEF

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Description, Type, and Default Values Element offset definition. A flag to determine how shell elements and bar and beam elements behave when the supplies ZOFF values on the shell connection entries (CQUAD4, CQUADR, CTRIA3, CTRIAR, CQUAD8, and CTRIA6) and WiA and WiB on CBAR, CBEAM, and CBEAM3 connection entries. (Character)

ELMOFF

Standard Nastran offset method. The ZOFF rotate with the shell element. The WiA and WiB offsets for beams are fixed. MSC Nastran 2008 and earlier. (Character, Default)

LROFF

Large rotation offsets. The shell normal directions are used to define the offset direction at each shell grid. New for MSC Nastran 2010. This method allows for thermal load effects on ZOFF for shells and WiA and WiB for beams. Thermal load effect for offset is computed based on the grid point or element temperature, and thermal coefficient of the element (see NOTHRM). The mass moment of inertia is computed for the offset due to the grid point location change introduced by offset. Differential stiffness is computed for the offset using the same method as that of the Lagrange formulation of the RBAR. (Character)


Name

Description, Type, and Default Values NODIF

LROFF is used but the differential stiffness effect is turned off. (Character)

NOTHRM

LROFF is used but the thermal load effects are turned off. The thermal load has two effects: 1) the location of thermal load changes due to offset and 2) the length of offset changes due to thermal load. Effect (1) is computed for all solution sequences and Effect (2) is computed for MSC Nastran SOL 400 only. Both effects are turned off by NOTHRM. (Character)

NODT

LROFF is used but the differential stiffness and thermal load effect are turned off. (Character)

ELMZ

LROFF is used but the element z-direction is used for the offset direction. IF PARAM, SNORM, 0.0 or the computed value for SNORM is greater then the PARAM,SNORM,value, then the LROFF option will revert to this method for CQUAD4, CTRIA3, CQUADR, and CTRIAR. (Character)

NOMASS

LROFF is used but the no mass effects are included. (Character)

NDMTZ

LROFF is used but the element z-direction is used for the offset direction and the differential stiffness, the thermal load effects, and the mass effects are turned off. For CQUAD4 and CTRIA3 elements this method should get similar results to the standard ELMOFF method. (Character)

Notes:

This entry only effects ZOFF calculations for ZOFF specified on the shell connection entries. For ZOFF specified on the PCOMP or PCOMPG entries, the standard ELMOFF method will be used. For CBEAM, CBAR, CQUAD8 and CTRIA6 elements, the LROFF option will revert to the ELMZ sub option.

If the computed value for SNORM is greater then the PARAM,SNORM,value and the wishes not to change the parameter value, the Bulk Data entry SNORM can be used to override the shell normal. Solution sequences affected: For linear - all solution sequences. For MSC Nastran - SOL 400 nonlinear only. The new method is not implemented into SOL 106 and 129. Note that there is no Case Control modification or other modifications to the input file required. By default, the old offset definition is used (MDLPRM,OFFDEF,ELMOFF)

Output There is no new output associated with the new offset methodology.

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Guidelines and Limitations Solution Sequences and Element Type to be ed by Offset Solution sequences and element types ed by the new offset method are: • All linear solutions sequences such as SOL 101, 103, 105, and dynamic solution sequences are

ed by the new offset method. • For nonlinear solution sequences, only SOL 400 is ed. SOL 106 and SOL 129 use the old

offset method. • For linear solution sequences, the new offset method s the following elements: QUAD4,

TRIA3, QUADR, TRIAR, BEAM, BAR, BEAM3, QUAD8, and TRIA6. • For SOL 400, the new offset s QUAD4, TRIA3, QUADR, TRIAR, and BEAM. • For advanced nonlinear elements in SOL 400, in addition to QUAD4, TRIA3, QUADR, TRIAR

and BEAM elements, QUAD8, TRIA6 and AXISYM are also ed. For QUAD4 and TRIA3, the stiffness for drilling DOF’s is zero. The offset is not completely constrained by the elements. For the linear solution sequences, this will not create any problem. For nonlinear analysis, this will not impede the solution of QUAD4/TRIA3 for most cases. However, for certain type of models, especially if the model is completely flat, the zero stiffness will make the solution with offset difficult to converge in SOL 400. If this happens, a large value K6ROT, in the order of 1,000.0 - 10,000.0, may be used to resolve this problem. Another work around is to use the QUADR/TRIAR elements. The new offset method has not been implemented for composites using the PCOMP or PCOMPG Bulk Data entries. For these entries, the needs to transfer the offset definition to the connection entries in order to use the new offset method.

Test Problems The following test cases are available in the TPL in directory /tpl/offsetmeth: TPL Example ofsl014.dat This example is a simple cantilever with offsets, model by QUAD4 and TRIA3 to obtain solution in the linear buckling analysis (SOL 105). There are two types of element in the file. The first subcase is preload. The second subcase is for QUAD4 and the third subcase is for TRIA3. Both loading and geometry are exaggerated to show the differential effect of offset. Bulk data input required for new offsets: “MDLPRM, OFFDEF, LROFF” The first buckling factor for both QUAD4 and TRIA3 are 1.52 with differential stiffness of offset. However, if we ignore the differential stiffness of offset (OFFDEF=NODIFF), the first buckling factor is 6087.

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Figure 7-9

TPL example problem ofsl014.dat

TPL Example ofslq416.dat This example is a cylindrical shell to demonstrate the effect of shell normal using linear static analysis SOL 101. Bulk data input required for new offsets: “MDLPRM, OFFDEF, LROFF” In this example, both elastic element stiffness and mass matrix are computed based on the offset geometry of the model. Since the shell normal is used as the direction of the offset, there is no gap in the geometry. For this model, the weight for shell normal model (OFFSET=LROFF) is 120.8, while for the z-direction model (OFFSET=ELMZ) the weight = 109.8. Results are obtained from grid point weight table. The displacement at T1 of grid 1 is 0.1095. However, if we use offset in z-direction (OFFDEF=ELMZ), then the corresponding displacement is 0.0996.

Figure 7-10

TPL example problem ofslq416.dat

TPL Problem ofsnbm01.dat This example is for the nonlinear solution of SOL 400. A simple cantilever beam is modeled by BEAM with offset. Bulk data input required for new offsets: “MDLPRM, OFFDEF, LROFF”. Both geometry and loads are exaggerated to show effects of offset and geometric nonlinear. In this model, the large rotation theory and differential stiffness are computed for the offsets of beam. This model is verified by explicitly modeling the offset by RBAR element. Both offset and RBAR give the same results.

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Figure 7-11

TPL example problem ofsnbm01.dat

GUI Patran Currently Patran does not the definition of MDLPRM,OFFDEF,offdef. However, it is expected that this will be ed in Patran 2008r3. SimXpert SimXpert s the definition of MDLPRM,OFFDEF,option. Figure 7-12 shows the GUI interface.

Figure 7-12

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SimXpert for MDLPRM,OFFDEF,option


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Chapter 8: MiscellaneousMSC Nastran 2010 Release Guide

8

Main Index

Miscellaneous 

Enhanced MONSUM



PARAM,NONCUP Usage Extended to SOL 111



Application Regions



New Input File Reader - IFPSTAR



Brake Squeal Analysis



Results and Output Changes



MSC Nastran Error List

134 MSC Nastran 2010 Release Guide Enhanced MONSUM

Enhanced MONSUM Introduction The MONSUM Bulk Data entry was introduced in MSC Nastran 2007 to enable the linear combination of monitor results or the updating in place of a monitor result. The MSC Nastran 2007 implementation imposed the restriction that the results to be summed must be of the same type. This restriction has been relieved in the current delivery.

Benefits The MONSUM feature of MSC Nastran 2007 allowed to to perform such tasks as units conversion on a monitor result or to combine similar types on monitor results. s also felt a need to combine different types of monitor points to create a special purpose response that is meaningful in the analysis task at hand. This extension of the MONSUM provides this added capability.

Feature Description The enhanced MONSUM, 2527 Bulk Data entry is described in the MD Nastran Quick Reference Guide. “Legacy” input files are ed in that the alternate format shown in the guide is identical to the standard format of earlier releases. A remark in the MONSUM description indicates that the summed quantities must be of a similar type, specifically: Force and moment summation monitor points: AMONPNT1, SMONPNT1, MONPNT3 Displacement monitor points: AMONDSP1 and SMONDSP1

Example Two examples are provided in the TPL: Monsum2.dat – This is a SOL 144 file that has five MONSUM entries. Three of these demonstrate the legacy feature while one combines an aerodynamic monpnt1 and a monpnt3 and another combines a structural monpnt1 with an aerodynamic monpnt1. Monsum4.dat – This is another SOL 144 file that has a single MONSUM entry that combines a structural mondsp1 with an aerodynamic mondsp1.

Guidelines and Limitations The MSC Nastran 2007 Release Guide and the previous examples imply this is a SOL 144 capability. This is not the case in that it can also be used in SOLs 101, 103, 108, 109, 111, 112 and 200. Summing a MONPNT1 and MONPNT3 in the dynamic solution sequences is currently misleading since the MONPNT1 inertia results while the MONPNT3 does not.

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CHAPTER 8 135 Miscellaneous

The summed results are printed as one of the monitor types with the following order of precedence: smonpnt1, smondsp1, monpnt3, amonpnt1, amondsp1. E.g., an amonpnt1 and a monpnt3 appearing on the same entry will result in a monpnt3 regardless of which appears first. If different monitor results are being summed, the NAME appearing on the MONSUM should be unique with respect to other names. For the update in place, the name can be the same.

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136 MSC Nastran 2010 Release Guide PARAM,NONCUP Usage Extended to SOL 111

PARAM,NONCUP Usage Extended to SOL 111 Until now, the usage of PARAM,NONCUP was allowed only in SOL 112, not in SOL 111. In MD Nastran 2010, usage of this parameter is allowed in SOL 111 also. In both SOLs 111 and 112, PARAM,NONCUP has the same meaning as follows:

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NONCUP = -1

Use uncoupled solution if there are no off-diagonal in any of the modal matrices (MHH, BHH, and KHH); otherwise use coupled solution.

NONCUP > -1

Use coupled solution regardless of the existence of off-diagonal in the modal matrices.

NONCUP = -2

Use uncoupled solution regardless of the existence of off-diagonal in the modal matrices.


Application Regions Introduction A new set concept called SET3 has been added which allows one to group together a list of nodes, elements, properties or a list of points and associate them with a unique id.

Benefits Application region can be used for group the elements or nodes. It is necessary for total heat load, loads, super element radiation load, and primitive radiation load. It is more convenient for the translator to process the groups of FEM data.

Input SET3 entry is used to define the application regions.

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138 MSC Nastran 2010 Release Guide New Input File Reader - IFPSTAR

New Input File Reader - IFPSTAR The IFPStar component is MSC Software’s enhanced bulk data processor that is introduced in MD Nastran 2010 and MSC Nastran 2010. IFP stands for Input File Processor. The IFPStar component utilizes MSC’s Simulation Component Architecture (SCA) framework, and provides a robust mechanism to that the your input is both correct and accurate.

Benefits The benefits of the IFPStar component include: • Faster input processing (up to 40% faster for typical large models) • SORT is not required before interpretation • Significantly lower memory requirements • Clearer error messaging • Rule based definition identifies exact entry and field of illegal data • Identification of which INCLUDE file / line number of an illegal entry • Uses Quick Reference Guide rule base • Provides consistent and rigorous rule checking • Template definition of fields provides easier implementation of new features, thus reducing

development time. • Higher precision of input tables – 64bit maintained • The higher precision may cause slightly different answers compared to previous versions or

models run with the old Input File Processor (IFP) • Replaces IFP, RMDUPBK, and XSORT modules with a single more efficient module • Extensible and Pluggable to in-house or external applications (future) • Simplifies the process of adding new entries

IFPStar significantly improves developers’ ability to add or modify Nastran bulk data entries in a very short amount of time (less than 3 hours for a very complex entry, comparing to days using legacy IFP module). Rather than ad-hoc parsing rules buried in multiple layers of code, within the application, IFPStar utilizes template-based definitions for entries, which simplifies the process of adding new fields, putting proper checks in place on the fields within an entry, adding boundary conditions, etc … Another advantage of IFStar component is that it leverages the “component” capability of the SCA framework, which means the component can be used in any SCA enabled application (in house or external), and can easily be updated in the field, without the need for updating the entire installation.

Detailed error messages The error messages that are created in the IFPStar component are aimed to better help engineers pinpoint their input errors. For example, let’s assume that a makes the following mistake in a SPC entry:

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SPC1

IO

12

1

3

1

3

The correct entry is: SPC1

10

12

Both IFPStar component and legacy IFP module catch the ’s error, and below is how each one issues the error messages: Legacy IFP module: *** FATAL MESSAGE 315 (IFPDRV) FORMAT ERROR ON BULK DATA ENTRY SPC1 SPC1 IO 12 1 3 *** FATAL MESSAGE 316 (IFPDRV) ILLEGAL DATA ON BULK DATA ENTRY SPC1 SPC1 IO 12 1 3 IFPStar Component: *** FATAL MESSAGE 9994 (BULKPM) Term Violation for Entity: SPC1 near line 27 SID:IO is an illegal integer value.

Potential Behavior Differences Note that IFPStar enforces the current Bulk Data rule set in the Quick Reference Guide. This means that legacy models that may have worked in previous versions may fail with IFPStar. Typical causes are illegal input that was not previously trapped, undocumented features or obsolete input entries. Note that there are several entries that are only ed by the IFPStar component in MSC Nastran 2010 and MSC Nastran 2010. These entries include:

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PRJCON

MAXBRG

FSICTRL

WETLOAD

WETSURF

WETELMG

WETELME

MATUDS

PRPUDS

BCONUDS

ELEMUDS

QUDS

RARM

MAT6

MATT6

RADC

RADCT

VIEWEX

PCONV1

PRIM1

PRIM2

PRIM3

PRIM4

PRIM5

PRIM6

PRIM7

PRIM8

TABLEU1

TABLEU2

ENTUDS

RADCOL

DTABLE2

MATUSR

MATTUSR

140 MSC Nastran 2010 Release Guide New Input File Reader - IFPSTAR

In RESTART runs, the “/” bulk data has been enhanced to have more friendly commands. Previously, the only options on the “/” bulk data entry were to remove specific sorted bulk data line numbers, but with IFPStar the delete directives are more friendly. Please refer to the Quick Reference Guide for more details. The sorted bulk data (print/punch) will have a slightly different look. In future versions of MSC Nastran and MSC Nastran new bulk data entries will only be ed by the IFPStar component.

Known Issues In addition to the entries listed above, there are a few items that will not work with the IFPStar component. MSGMESH is no longer ed. Basic replication entries are ed, but some advanced replication applications may not work. In this case, it is recommended to use the old IFP processor with the case control command ECHO=PUNCH to generate a bulk data input without replications. Since this is a brand new component, and Nastran has 30+ years of legacy, while all attempts have been made to the legacy, it is possible that some client models may not work with-in the bounds of IFPStar component rules and definitions. When this rare situation occurs with your existing models, you can get around this problem by using the old IFP by adding the following system cell nastran system(444)=0 to the top of your input file (see next paragraph for more details).

Changing the Defaults The NASTRAN System cell 444 is reserved to select the input file processor options. SYSTEM(444)=1 is the new default for the IFPStar component, SYSTEM(444)=0 is old IFP. These settings can be changed in the Patran Translation Parameters form and in the SimXpert Generic Solver Parameters form. In Patran 2010 and SimXpert 3.2 and earlier versions, the default can be changed in the Direct Text Input system cell section by adding "NASTRAN SYSTEM(444)=0" - without the quotes. It can also be selected by adding NASTRAN IFPSTAR=YES.

If You Find Errors If you encounter an entry that follows the Quick Reference Guide rules and does not contain undocumented fields, but fails in the IFPStar component, please MSC .

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Brake Squeal Analysis The brake squeal option available in MSC Nastran 2008 was limited to (1) linear finite elements and (2) a single rotation axis. Since there are quite some applications where quadratic finite elements are preferred to linear finite elements, in MSC Nastran 2010 both linear and quadratic finite elements are ed in a brake squeal analysis. Moreover, in Sol600, the limitation of a single rotation axis has been removed, so that it is possible to model e.g. multiple gear wheel combinations in a single analysis, where per pair of bodies a different rotation axis can be specified. To this end, an alternate format of the BSQUEAL entry has been introduced, where the field entry "BODY" signals the start of data for a pair of bodies.

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142 MSC Nastran 2010 Release Guide Results and Output Changes

Results and Output Changes Change of Solution Method for Dynamic Enforced Motion Analysis Using SPC/SPCD The total solution of a dynamic enforced motion analysis using SPC/SPCD can be regarded as a combination of a static enforced motion solution (similar to what is done in SOL 101) and a dynamic enforced motion solution that is relative to this static-based solution. Two methods are employed for obtaining the solution in Nastran. In the total or absolute (TOTAL/ABS) motion method, the program solves directly, in one step, for the TOTAL solution of the dynamic analysis which includes both the static-based solution and the dynamic solution that is relative to the static-based solution. In the relative (REL) motion method, the program obtains the total solution of the dynamic analysis in two steps, by first solving for the static-based solution and then solving separately for the dynamic solution RELATIVE to the static-based solution. The TOTAL/ABS solution method is computationally more efficient. This is also the only method that is meaningful and that should be employed when a problem involves the use of NOLINi or NLRGAP entries. An important point to note regarding this method is that, for modal dynamic analysis, residual vectors are absolutely critical in order for this method to get correct answers. The REL solution method, though less efficient, may be more accurate for transient solutions and for modal frequency response solutions at very low forcing frequencies. Also, for modal dynamic analysis, this method is not as critically dependent on residual vectors as the TOTAL/ABS solution method. In pre-MSC Nastran 2010 versions of Nastran, the TOTAL/ABS method did not modal damping and fluid structure problems. These problems are now fully resolved. With these enhancements, the TOTAL/ABS and REL solution methods both yield essentially the same results. In earlier versions of Nastran, the REL method was the implied default solution method. However, because of efficiency and other considerations outlined above, the TOTAL/ABS method has been chosen to be the default solution method in MSC Nastran 2010. (See also related discussion below.)

New ENFMETH Parameter There is a parameter called ENFMETH that controls the solution method when dynamic enforced motion analysis via SPC/SPCD is used in SOLs 108, 109, 111, 112, 146 and 200. This parameter was an undocumented parameter in earlier versions and was used internally with an implied default value of REL, implying the use of the REL solution method mentioned above. This parameter is now documented in the ENFMETH (p. 723) in the MD/MSC Nastran Quick Reference Guide and the default value has been changed to TOTAL (or ABS) to reflect the new default of the TOTAL/ABS solution method indicated above. It should be emphasized here that the new ENFMETH parameter is completely separate, independent and distinct from the similarly sounding ENFMOTN parameter. These two parameters should not be confused with each other. The former controls the solution method when dynamic enforced motion analysis via SPC/SPCD is used while the latter controls how the results of such an analysis are output.

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Details will be clear from the descriptions of these parameters in the ENFMETH and ENFMOTN (p. 724) in the MD/MSC Nastran Quick Reference Guide.

NEW OPTMIZER Optimization tasks that previously used the BIGDOT optimization algorithm now employ the IPOPT optimization algorithm (See The IPOPT Algorithm (App. C) in the Design Sensitivity and Optimization ’s Guide). These are typically topology optimization tasks or tasks with many design variables. If the explicitly selects the BIGDOT algorithm using OPTCOD=BIGDOT on the DOPTPRM bulk data entry, the IPOTPT algorithm will be used in its place and a Information Message will be printed that indicates this. It is expected that the results from the two algorithms will be similar, but not exactly the same.

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144 MSC Nastran 2010 Release Guide MSC Nastran Error List

MSC Nastran Error List The current error lists for MSC Nastran can be obtained from the MSC Software Simcompanion website: http://simcompanion.mscsoftware.com/infocenter/index?page=content&id=KI8008006

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Ap. A: Connectors MSC Nastran 2010 Release Guide

A

Connectors



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Connectors Output

146 MSC Nastran 2010 Release Guide Connectors Output

Connectors Output Example A - Element Force and Element Stress 0

FREQUENCY =

ELEMENT ID 30 0

BEND-MOMENT END-A PLANE 1 (MZ) PLANE 2 (MY) -1.808122E-01 -1.966379E-02 2.170022E-02 2.359719E-03

FREQUENCY =

ELEMENT ID 30 0

BEND-MOMENT END-A PLANE 1 (MZ) PLANE 2 (MY) -1.808791E-01 -1.966534E-02 2.171652E-02 2.360096E-03 1.000000E+01 C O M P L E X

AXIAL STRESS 3.525211E+00 -4.228557E-01

FREQUENCY =

ELEMENT ID 30

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2.000000E+01 C O M P L E X

FREQUENCY =

ELEMENT ID 30 0

1.000000E+01 C O M P L E X


BEND-MOMENT END-B PLANE 1 (MZ) PLANE 2 (MY) -3.561784E-03 2.373087E-03 4.290746E-04 -2.845342E-04 F O R C E S

S T R E S S E S


- SHEAR PLANE 1 (FY) PLANE 2 (FZ) -3.980280E-01 -4.946850E-02 4.777317E-02 5.934670E-03



AXIAL FORCE FX TORQUE MX 2.765457E-02 2.769116E-02 -3.313215E-03 3.328268E-03 SUBCASE 1

( C W E L D P )




AXIAL FORCE FX TORQUE MX 2.768694E-02 -2.765884E-02 -3.321101E-03 3.320390E-03 SUBCASE 1

( C W E L D P )



S T R E S S E S

( C W E L D P )

- SHEAR PLANE 1 (FY) PLANE 2 (FZ) -3.979684E-01 -4.947790E-02 4.775866E-02 5.936962E-03


BEND-MOMENT END-B PLANE 1 (MZ) PLANE 2 (MY) -3.602137E-03 2.367348E-03 4.389053E-04 -2.831364E-04


2.000000E+01 C O M P L E X

AXIAL STRESS 3.521090E+00 -4.218517E-01

SUBCASE 1 F O R C E S

MAXIMUM SHEAR STRESS 2.092356E+02 2.511545E+01

BEARING STRESS 4.010323E+01 4.812626E+00 SUBCASE 1

( C W E L D P )


MAXIMUM SHEAR STRESS 2.094103E+02 2.515803E+

BEARING STRESS 4.010902E+01

Appendix A 147 Connectors

Example B - Element Stress Output 0 ELEMENT-ID 10001

10002

Main Index

CORNER GRID-ID 0GRID CENTER X Y Z 90001 X Y Z 90002 X Y Z 90003 X Y Z 90004 X Y Z 90005 X Y Z 90006 X Y Z 90007 X Y Z 90008 X Y Z 0GRID CENTER X Y Z 90009 X Y Z 90010 X Y Z 90011 X Y Z

S T R E S S E S I N S E A M E L E M E N T S ( C S ------CENTER AND CORNER POINT STRESSES--------DIR. COSINES NORMAL SHEAR PRINCIPAL -A- -B- -CCS 8 GP 7.747896E+05 XY -3.827610E+03 A 7.748116E+05 LX 1.00 0.00-0.01 1.074136E+05 YZ 1.673470E-10 B 2.502929E-09 LY-0.01 0.00-1.00 2.328306E-09 ZX 1.746230E-09 C 1.073916E+05 LZ 0.00 1.00 0.00 1.711155E+06 XY -7.739222E+03 A 1.711200E+06 LX 1.00 0.00-0.01 3.764584E+05 YZ -3.868169E+03 B 3.602726E+05 LY-0.01 0.23-0.97 3.611997E+05 ZX -5.157554E+01 C 3.773406E+05 LZ 0.00 0.97 0.23 1.707039E+06 XY -7.739222E+03 A 1.707084E+06 LX 1.00 0.00-0.01 3.646422E+05 YZ 3.868169E+03 B 3.572576E+05 LY-0.01-0.47-0.88 3.592958E+05 ZX -5.157554E+01 C 3.666358E+05 LZ 0.00 0.88-0.47 -1.638654E+05 XY 8.400235E+01 A -1.563204E+05 LX 0.01 0.00-1.00 -1.563954E+05 YZ 3.868169E+03 B -3.583610E+05 LY 1.00-0.02 0.01 -3.582869E+05 ZX -5.157554E+01 C -1.638663E+05 LZ 0.02 1.00 0.00 -1.655750E+05 XY 8.400235E+01 A -1.580980E+05 LX 0.01 0.00-1.00 -1.581723E+05 YZ -3.868169E+03 B -3.622819E+05 LY 1.00 0.02 0.01 -3.622085E+05 ZX -5.157554E+01 C -1.655759E+05 LZ-0.02 1.00 0.00 1.727548E+06 XY -7.739222E+03 A 1.727593E+06 LX 1.00 0.00-0.01 3.830623E+05 YZ -3.868169E+03 B 3.659432E+05 LY-0.01 0.22-0.98 3.668194E+05 ZX 5.157554E+01 C 3.838939E+05 LZ 0.00 0.98 0.22 1.722568E+06 XY -7.739222E+03 A 1.722612E+06 LX 1.00 0.00-0.01 3.703815E+05 YZ 3.868169E+03 B 3.612509E+05 LY-0.01-0.39-0.92 3.628978E+05 ZX 5.157554E+01 C 3.719841E+05 LZ 0.00 0.92-0.39 -1.698541E+05 XY 8.400235E+01 A -1.598039E+05 LX 0.01 0.00-1.00 -1.598779E+05 YZ 3.868169E+03 B -3.639800E+05 LY 1.00-0.02 0.01 -3.639066E+05 ZX 5.157554E+01 C -1.698548E+05 LZ 0.02 1.00 0.00 -1.706989E+05 XY 8.400235E+01 A -1.607165E+05 LX 0.01 0.00-1.00 -1.607901E+05 YZ -3.868169E+03 B -3.658836E+05 LY 1.00 0.02 0.01 -3.658106E+05 ZX 5.157554E+01 C -1.706996E+05 LZ-0.02 1.00 0.00 CS 8 GP 7.406084E+05 XY 9.462977E+02 A 7.406120E+05 LX 1.00 0.00 0.00 -2.130364E+04 YZ 4.292815E-10 B -2.130482E+04 LY 0.00 1.00 0.00 -1.583248E-08 ZX 1.333328E+03 C -2.400266E+00 LZ 0.00 0.00-1.00 1.623490E+06 XY 1.970375E+03 A 1.623494E+06 LX 1.00 0.00 0.00 8.306726E+04 YZ 9.464031E+02 B 8.306052E+04 LY 0.00 1.00 0.00 2.947562E+05 ZX 1.612613E+03 C 2.947584E+05 LZ 0.00 0.00-1.00 1.623357E+06 XY 1.970375E+03 A 1.623361E+06 LX 1.00 0.00 0.00 8.317433E+04 YZ -9.464031E+02 B 8.316755E+04 LY 0.00 1.00 0.00 2.942068E+05 ZX 1.612613E+03 C 2.942091E+05 LZ 0.00 0.00-1.00 -1.337316E+05 XY -7.777978E+01 A -1.233649E+05 LX-0.01-0.01-1.00 -1.233709E+05 YZ -9.464031E+02 B -2.949047E+05 LY 1.00 0.01-0.01 -2.948834E+05 ZX 1.612613E+03 C -1.337162E+05 LZ-0.01 1.00-0.01

E A M ) MEAN PRESSURE

VON MISES

-2.940678E+05

7.270885E+05

-8.162711E+05

1.342475E+06

-8.103257E+05

1.345162E+06

2.261826E+05

1.983753E+05

2.286519E+05

2.005495E+05

-8.258101E+05

1.352764E+06

-8.186157E+05

1.356026E+06

2.312129E+05

1.993407E+05

2.324332E+05

2.003621E+05

-2.397683E+05

7.514921E+05

-6.671043E+05

1.446252E+06

-6.669126E+05

1.446268E+06

1.839953E+05

1.666055E+05


0 ELEMENT-ID

10003

0 ELEMENT-ID 10004

Main Index

S T R E S S E S I N S E A M E L E M E N T S ( C S E ------CENTER AND CORNER POINT STRESSES--------DIR. COSINES NORMAL SHEAR PRINCIPAL -A- -B- -CX -1.333445E+05 XY -7.777978E+01 A -1.228786E+05 LX-0.01-0.01-1.00 Y -1.228843E+05 YZ 9.464031E+02 B -2.941010E+05 LY 1.00-0.01-0.01 Z -2.940796E+05 ZX 1.612613E+03 C -1.333288E+05 LZ 0.01 1.00-0.01 90013 X 1.608190E+06 XY 1.970375E+03 A 1.608193E+06 LX 1.00 0.00 0.00 Y 7.755697E+04 YZ 9.464031E+02 B 7.755026E+04 LY 0.00 1.00 0.00 Z 2.916883E+05 ZX 1.054044E+03 C 2.916916E+05 LZ 0.00 0.00-1.00 90014 X 1.608294E+06 XY 1.970375E+03 A 1.608298E+06 LX 1.00 0.00 0.00 Y 7.790112E+04 YZ -9.464031E+02 B 7.789438E+04 LY 0.00 1.00 0.00 Z 2.916921E+05 ZX 1.054044E+03 C 2.916954E+05 LZ 0.00 0.00-1.00 90015 X -1.357683E+05 XY -7.777978E+01 A -1.230557E+05 LX-0.01-0.01-1.00 Y -1.230615E+05 YZ -9.464031E+02 B -2.918279E+05 LY 1.00 0.01-0.01 Z -2.918155E+05 ZX 1.054044E+03 C -1.357617E+05 LZ-0.01 1.00-0.01 90016 X -1.356183E+05 XY -7.777978E+01 A -1.228063E+05 LX-0.01-0.01-1.00 Y -1.228120E+05 YZ 9.464031E+02 B -2.915773E+05 LY 1.00-0.01-0.01 Z -2.915649E+05 ZX 1.054044E+03 C -1.356115E+05 LZ 0.01 1.00-0.01 0GRID CS 8 GP CENTER X 1.284104E+03 XY -4.129671E+01 A 1.285049E+03 LX 1.00 0.02 0.00 Y -5.206752E+02 YZ 6.457412E-10 B -5.216197E+02 LY-0.02 1.00 0.00 Z -2.142042E-08 ZX 8.847564E-08 C -2.142039E-08 LZ 0.00 0.00-1.00 90017 X 2.416318E+03 XY -5.225373E+01 A 2.417096E+03 LX 1.00 0.01 0.00 Y -1.092519E+03 YZ -4.401031E+01 B -1.094830E+03 LY-0.01 1.00 0.03 Z 1.684483E+02 ZX -5.868064E-01 C 1.699818E+02 LZ 0.00 0.03-1.00 90018 X 2.495232E+03 XY -5.225373E+01 A 2.496019E+03 LX 1.00 0.02 0.00 Y -9.753662E+02 YZ 4.401031E+01 B -9.776510E+02 LY-0.02 1.00-0.03 Z 3.143401E+02 ZX -5.868064E-01 C 3.158376E+02 LZ 0.00-0.03-1.00 90019 X -8.759534E+01 XY -3.033968E+01 A -2.349008E+01 LX-0.42-0.08-0.91 Y -5.015059E+01 YZ 4.401031E+01 B -1.968506E+02 LY 0.88-0.30-0.38 Z -1.829433E+02 ZX -5.868064E-01 C -1.003486E+02 LZ 0.24 0.95-0.19 90020 X -1.375186E+02 XY -3.033968E+01 A -7.612272E+01 LX-0.44 0.04-0.90 Y -9.965966E+01 YZ -4.401031E+01 B -3.093700E+02 LY 0.88 0.21-0.42 Z -2.998451E+02 ZX -5.868064E-01 C -1.515307E+02 LZ-0.17 0.98 0.13 90021 X 2.982642E+03 XY -5.225373E+01 A 2.983355E+03 LX 1.00 0.01 0.00 Y -8.465572E+02 YZ -4.401031E+01 B -8.487935E+02 LY-0.01 1.00 0.03 Z 4.219966E+02 ZX 5.868065E-01 C 4.235193E+02 LZ 0.00 0.03-1.00 90022 X 2.948929E+03 XY -5.225373E+01 A 2.949649E+03 LX 1.00 0.01 0.00 Y -8.420306E+02 YZ 4.401031E+01 B -8.444359E+02 LY-0.01 1.00-0.04 Z 3.050948E+02 ZX 5.868065E-01 C 3.067800E+02 LZ 0.00-0.04-1.00 90023 X -2.039378E+02 XY -3.033968E+01 A -1.402171E+02 LX-0.43-0.02-0.90 Y -1.611178E+02 YZ 4.401031E+01 B -4.434710E+02 LY 0.90-0.16-0.42 Z -4.364915E+02 ZX 5.868065E-01 C -2.178590E+02 LZ 0.13 0.99-0.09 90024 X -1.412352E+02 XY -3.033968E+01 A -7.500764E+01 LX-0.41 0.04-0.91 Y -9.800105E+01 YZ -4.401031E+01 B -3.004030E+02 LY 0.89 0.22-0.39 Z -2.905998E+02 ZX 5.868065E-01 C -1.544254E+02 LZ-0.18 0.98 0.12

CORNER GRID-ID 90012

CORNER GRID-ID 0GRID CENTER X Y Z 90025 X Y Z 90026 X Y Z 90027 X Y Z 90028 X Y Z 90029 X Y Z 90030 X Y Z 90031 X Y Z 90032 X Y Z

S T R E S S E S I N S E A M E L E M E ------CENTER AND CORNER POINT STRESSES--------NORMAL SHEAR PRINCIPAL CS 8 GP 2.857427E+00 XY -5.724032E-02 A 7.595094E+00 7.594403E+00 YZ -5.420588E-10 B 1.257286E-08 1.257285E-08 ZX -6.053597E-09 C 2.856735E+00 1.577084E+00 XY 5.002377E+00 A 6.410882E+00 1.218060E+00 YZ 1.910919E-01 B -3.610427E+00 4.063272E+00 ZX 2.547832E-03 C 4.057961E+00 -5.694098E+00 XY 5.002377E+00 A -8.618130E-01 -6.043215E+00 YZ -1.910919E-01 B -1.292361E+01 -1.291273E+01 ZX 2.547832E-03 C -1.086462E+01 3.802032E+00 XY -5.116858E+00 A 1.589757E+01 1.373110E+01 YZ -1.910919E-01 B -4.134058E+00 -4.131593E+00 ZX 2.547832E-03 C 1.638033E+00 1.120986E+01 XY -5.116858E+00 A 2.345315E+01 2.131121E+01 YZ 1.910919E-01 B 9.069369E+00 1.298105E+01 ZX 2.547832E-03 C 1.297959E+01 -5.801891E+00 XY 5.002377E+00 A -9.705124E-01 -6.152861E+00 YZ 1.910919E-01 B -1.313789E+01 -1.312748E+01 ZX -2.547842E-03 C -1.097383E+01 1.536345E+00 XY 5.002377E+00 A 6.378676E+00 1.195284E+00 YZ -1.910919E-01 B -3.641881E+00 3.985157E+00 ZX -2.547842E-03 C 3.979991E+00 1.171584E+01 XY -5.116858E+00 A 2.348970E+01 2.126247E+01 YZ -1.910919E-01 B 9.489802E+00 1.305916E+01 ZX -2.547842E-03 C 1.305798E+01 4.514247E+00 XY -5.116858E+00 A 1.643190E+01 1.423316E+01 YZ 1.910919E-01 B -3.919224E+00 -3.916836E+00 ZX -2.547842E-03 C 2.317893E+00

A M ) MEAN PRESSURE 1.834361E+05

VON MISES 1.662438E+05

-6.591450E+05

1.435601E+06

-6.592958E+05

1.435494E+06

1.835484E+05

1.627915E+05

1.833317E+05

1.627466E+05

-2.544763E+02

1.610510E+03

-4.974160E+02

3.080820E+03

-6.114019E+02

3.040780E+03

1.068964E+02

1.504556E+02

1.790078E+02

2.061600E+02

-8.526937E+02

3.380599E+03

-8.039978E+02

3.369357E+03

2.671824E+02

2.728479E+02

1.766120E+02

1.980148E+02

N T S ( C S E A M ) DIR. COSINES MEAN -A- -B- -RESSURE LX-0.01 0.00-1.00 LY 1.00 0.00-0.01 LZ 0.00 1.00 0.00 LX 0.72-0.69 0.05 LY 0.69 0.72 0.03 LZ 0.06-0.02-1.00 LX 0.72-0.04 0.69 LY 0.69 0.06-0.72 LZ-0.01 1.00 0.07 LX-0.39 0.01-0.92 LY 0.92 0.01-0.39 LZ-0.01 1.00 0.01 LX-0.39 0.92-0.02 LY 0.92 0.39 0.01 LZ 0.02-0.02-1.00 LX 0.72 0.04 0.69 LY 0.69-0.05-0.72 LZ 0.01 1.00-0.06 LX 0.72-0.69-0.05 LY 0.69 0.72-0.03 LZ-0.06 0.02-1.00 LX-0.40 0.92 0.03 LY 0.92 0.40-0.01 LZ-0.02 0.02-1.00 LX-0.39-0.01-0.92 LY 0.92-0.01-0.39 LZ 0.01 1.00-0.01

VON MISES

-3.483943E+00

6.644488E+00

-2.286139E+00

9.076537E+00

8.216681E+00

1.117548E+01

-4.467181E+00

1.785942E+01

-1.516737E+01

1.288174E+01

8.360745E+00

1.124266E+01

-2.238929E+00

9.062510E+00

-1.534583E+01

1.260059E+01

-4.943524E+00

1.805928E+01

Appendix A 149 Connectors

Main Index


Main Index

Msc Nastran 2010 Release Guide 4dgs

Overview 3e4r5l

More details w3441

Related Documents 3m3m1z

Msc Nastran 2010 Release Guide 4dgs

Md/msc Nastran 2010 Quick Reference Guide 125961

Msc Nastran Quick Reference Guide Msc Nastran 2012 Quick Reference Guide 1d153y

How To Install Msc Nastran 6q1p3z

Fully Stressed Design In Msc - Nastran 4x4r43

Nastran Optimization Guide o4