patran 弹簧单元有限元分析

WORKSHOP 32aSpring Element with Nonlinear

Analysis Parameters(large displacements off)Objectives:sDemonstrate how to run a simple linear analysis in SOL

106 (nonlinear statics).sDemonstrate how to interpret the stand the difference between linear and nonlinear

n 105 Exercise Workbook32a-1

n 105 Exercise Workbook

WORKSHOP 32aSpring Element w/ Nonlin ParamsModel Description:For the structure below:YCRODA = 0.01 in2E = 1.E7 psiL = 10.0 inK = 1.E3 lb/inP = 29.E3 lbsXCELAS1Add Case Control commands and Bulk Data Entries to:m a geometric linear analysis in SOL 106

(nonlinear statics) with the large displacements option

turned a 29x103incremented steps. Use the default values for all other

lbs load in a single subcase with four

subcase parameters. Request the output of all grid

displacements and all element n 105 Exercise Workbook32a-3

Suggested Exercise Steps:sModify the existing n input file by adding the

appropriate loading conditions and nonlinear static analysis

control t Element Forces as part of the output (FORCE=ALL).sFor Case Control, insert the static load set selection (LOAD)

and the nonlinear static analysis parameter selection

(NLPARM).sFor Bulk Data, insert the relevant nonlinear static analysis

parameter (NLPARM).sPrepare the model for a geometric linear static analysis (turn

off large displacements).xPARAM, LGDISP, -1sGenerate an input file and submit it to the n

solver for a nonlinear static w the n 105 Exercise Workbook

WORKSHOP 32aSpring Element w/ Nonlin ParamsInput File for Modification: NAS103, WORKSHOP 32ATIME 10SOL 106 $ NONLINCENDTITLE=SIMPLE ROD SPRING - COLD ANALYSIS AND RESTART WORKSHOPSUBTITLE=GEOMETRIC NONLINEARECHO=BOTHDISP=ALLOLOAD=ALL$$ APPLY X LOAD$SUBCASE 10 $ LOAD=29.E03 LABEL=APPLY LOAD P IN X DIRECTION = 29E+03OUTPUT(PLOT) SET 1 ALL MAXI DEFO 5. AXES Z, X, Y VIEW 0., 0., 0. FIND SCALE ORIGIN 1 SET 1 PLOT STATIC 0 MAXIMUM DEFORMATION 5. SET 1BEGIN BULKGRID, 1, 0, 0.0, 0.0, 0.0, , 23456GRID, 3, 0, 0.0, 10.0, 0.0, , 123456CROD, 3, 3, 3, 1CELAS1, 2, 2, 1, 1, 0PROD, 3, 3, .01PELAS, 2, 1.0E3MAT1, 3, 1.0E7FORCE, 1, 1, 0, 1.6E4, 1.0FORCE, 2, 1, 0, 2.4E4, 1.0FORCE, 3, 1, 0, 2.9E4, n 105 Exercise Workbook32a-5

Exercise Procedure: who are not utilitizing

for generating an input file should go to Step

12, otherwise, proceed to step a new database called /New Database NameOKIn the New Model Preference form set the following:Tolerance:Analysis Code:Analysis Type: who do not wish to set up the model themselvesmay want to play the session file, . If youchoose to build the model yourself, proceed to step 4.

prob32aq

DefaultMSC/NASTRANStructuralFile/Session File ListApplyThe model has now been created. Skip to Step er possible click

u Auto Execute

(turn off). a 10 unit long

GeometryAction:Object:Method:Vector Coordinate n 105 Exercise Workbook Create Curve XYZ<0, 10, 0>

WORKSHOP 32aSpring Element w/ Nonlin the curve with one BAR2 element.x Finite ElementsAction:Object:Type:Global Edge LengthElement Topology:Curve ListApplyFor clarity, increase the node size using the following toolbar icon: Create Mesh Curve10Bar2Curve 1(Select the curve.) the material property for the beam.x

MaterialsAction:Object:Method:Material Elastic Modulus = the property for the beam.1.E7 Create Isotropic Manual Inputmat_1x

PropertiesAction: n 105 Exercise Workbook32a-7

Dimension:Type:Property Set Material NameAreaOKSelect MembersAddApply8. 1D Rodprop_1m:mat_10.01Curve 1(Select the curve.)Create a grounded spring at the bottom of the , create a 0-D element to be used for spring constant assignmentat the bottom of the beam.x Finite ElementsAction:Object:Method:Shape:Topology:Node 1 =ApplyNext, create the grounded spring property for the newly createdelement. Create Element EditPointPointNode 1(Select the bottom node.)x PropertiesAction:Object:Method:n 105 Exercise Workbook Create 0D Grounded Spring

WORKSHOP 32aSpring Element w/ Nonlin ParamsProperty Set Spring ConstantDof at Node 1OKYou can either type in the point element into the databox or click onthe point itself. This is done by first, clicking the Select Membersdatabox and then clicking on the following icon.

Point Element1.E3UXprop_2Select Members:Elm 2(Select the point element previouslycreated.) the Loads/BCs for the , fix the top end of the beam.x

Loads/BCsAction:Object:Method:New Set Translation < T1 T2 T3 >Rotation < R1 R2 R3 >OKSelect < 0, 0, 0 >< 0, 0, 0 > Create Displacement Nodalconstraint_n 105 Exercise Workbook32a-9

Select Geometry Entities:AddOKApplyPoint 2

(Select point at top of beam.)Next, create the guided support Load/BC at the base (free in

x-direction, and fixed in all other DOFs).New Set Name:Translation < T1 T2 T3 >Rotation < R1 R2 R3 >

OKSelect Select Geometry the loading for the 1

(Select point at bottom of beam.)constraint_2< , 0, 0 >< 0, 0, 0 >For this analysis model, the load will be incremented up to the finalload in a single subcase.x

Loads/BCsAction:Object:Method:New Set Force n 105 Exercise Workbook Create Force Nodalload_3<29.E3, 0, 0>

WORKSHOP 32aSpring Element w/ Nonlin ParamsSelect Select Geometry EntitiesAddOKApplyYour viewport should now appear as follow:

Point 1

(Select point at bottom of beam.) you are ready to generate an input file for on the Analysis radio button on the Top Menu Bar and set up thesubcases as follows:x

AnalysisAction:Object:Method:Job Name Analyze Entire Model Analysis n 105 Exercise Workbook32a-11

Solution Type:(Turn off large displacements.)q NONLINEAR STATICË Large Available Subcases:Number of Load Increments:Output Requests:DeleteOutput Requests:DeleteSelect Result Type:OKApply

CancelApply

Element Forces

4DefaultAn input file called will be generated. This process oftranslating your model into an input file is called the ForwardTranslation. The Forward Translation is complete when the Heartbeatturns green. users should now proceed to Step n 105 Exercise Workbook

WORKSHOP 32aSpring Element w/ Nonlin ParamsGenerating an input file for n Users:n users can generate an input file using thedata from the Model Description. The result should besimilar to the output below ():ASSIGN OUTPUT2 = ’2’ , UNIT=12ID NAS103, WORKSHOP 32A SOLUTIONTIME 10SOL 106 $ NONLINCENDTITLE=SIMPLE ROD SPRING - COLD ANALYSIS AND RESTART WORKSHOPSUBTITLE=GEOMETRIC NONLINEARECHO=BOTHDISP=ALLOLOAD=ALLFORCE=ALL$$ APPLY X LOAD$SUBCASE 10 $ LOAD=29.E03 LABEL=APPLY LOAD P IN X DIRECTION = 29E+03 LOAD=3 NLPARM=10OUTPUT(PLOT) SET 1 ALL MAXI DEFO 5. AXES Z, X, Y VIEW 0., 0., 0. FIND SCALE ORIGIN 1 SET 1 PLOT STATIC 0 MAXIMUM DEFORMATION 5. SET 1BEGIN BULKPARAM, POST, -1PARAM, PATVER, 3.0GRID, 1, 0, 0.0, 0.0, 0.0, , 23456GRID, 3, 0, 0.0, 10.0, 0.0, , 123456CROD, 3, 3, 3, 1CELAS1, 2, 2, 1, 1, 0PROD, 3, 3, .01PELAS, 2, n 105 Exercise Workbook32a-13

MAT1, 3, 1.0E7FORCE, 1, 1, 0, 1.6E4, 1.0FORCE, 2, 1, 0, 2.4E4, 1.0FORCE, 3, 1, 0, 2.9E4, 1.0PARAM, LGDISP,-1NLPARM, 10, n 105 Exercise Workbook

WORKSHOP 32aSpring Element w/ Nonlin ParamsSubmit the input file for analysis: the input file to n for submit the .bdf file, find an availableUNIX shell window. At the command prompt enternastran scr=yes. Monitor the analysisusing the UNIX ps submit the n .dat file, find an availableUNIX shell window and at the command prompt enternastran scr=yes. Monitor the analysisusing the UNIX ps the analysis is completed, edit the prob32a.f06 fileand search for the word FATAL. If no matches exist,search for the word WARNING. Determine whetherexisting WARNING messages indicate modeling still editing prob32a.f06, search for the word:D I S P L A C E (spaces are necessary).What is the x-displacement of the guided end at the end ofthe analysis?T1 =What is the force in the spring element at the end of theanalysis?FORCE =n 105 Exercise Workbook32a-15

Comparison of Results:e the results obtained in the .f06 file with theresults on the following page:

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LOAD STEP = 1.00000E+00 D I S P L A C E M E N T V E C T O RPOINT ID. TYPE T1 T2 T3 R1 R2 R3 1 G 2.900000E+01 0.0 0.0 0.0 0.0 0.0 2 G 0.0 0.0 0.0 0.0 0.0 0.0 SUBCASE 1LOAD STEP = 1.00000E+00 F O R C E S I N S C A L A R S P R I N G S ( C E L A S 1 )ELEMENT FORCE ELEMENT FORCE ELEMENT FORCE ELEMENT FORCE ID. ID. ID. ID. 2 2.900000E+040 SUBCASE 1WORKSHOP 32aSpring Element w/ Nonlin n 105 Exercise Workbook32a-17

ends the exercise for n users should proceed to the next d with the Reverse Translation process, that is, importingthe 2 results file into . To do this, returnto the Analysis form and proceed as follows:x

AnalysisAction:Object:Method:Select Selected Results FileOKApply

the translation is complete bring up the Results form.

2 Read Output2 Result Entities TranslateNow we will generate the fringe plot of the model.x ResultsAction:

Object:

Create

Fringe

Now click on the Select Results Result Case(s)

Select Fringe Result

Quantity:

Default, PW Linear: 100.% of

Load

Displacements, TranslationalMagnitude

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WORKSHOP 32aSpring Element w/ Nonlin ParamsNext click on the Target Entities icon.

Target EntitiesTarget Entity: Current ViewportNote: This feature allows you to view fringe plots of specific elementsof your choice.

Click on the Display Attributes :

Display:

Discrete/Smooth Free Edges

For better visual quality of the fringe plot, change the width ofthe line.

Width:

(Select the third line from top.)Note: The Display Attributes form allows you the ability to changethe displayed graphics of fringe plots.

Now click on the Plot Options icon.

Coordinate Transformation:Scale Factor

Apply

None

1.0

The resulting fringe plot should display the displacement spectrumsuperimposed over the undeformed bar. The final fringe plotdisplaying the physical deformation of the model can be created asfollows:

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x ResultsAction:

Object:

Create

Deformation

Now click on the Select Results Result Case(s)

Select Fringe Result

Show As:

Default, PW Linear: 100.% of

Load

Displacements, Translational

Resultant

Click on the Display Attributes Width:

(Select the third line from top.)In order to see the deformation results accurately, set the ScaleInterpretation to True Scale with a Scale Factor of InterpretationScale Factor

s Show UndeformedLine Width:

(Select the third line from top.)q True Scale

1.0

Now click on the Plot Options nate Transformation:Scale Factor

Apply

n 105 Exercise Workbook None

1.0

WORKSHOP 32aSpring Element w/ Nonlin ParamsThe resulting fringe plot should display the displacement spectrum inaddition to the physical deformation of the model. The following stepwill combine the two previous plots into one. automatically combines both the fringe and deformation plots better fit the results on the screen, zoom out a couple times usingthe following toolbar icon:Alternatively, use any number of the toolbar icons to better view theresulting fringe viewport should now contain the following image:Notice that the deflection is almost 3 times the length of the beam!This suggests that a nonlinear analysis which accounts for largedisplacements is necessary to obtain a more accurate clear the post-processing results and obtain the original model inthe viewport, select the Reset Graphics when you have completed this n 105 Exercise Workbook32a-21

.bdf file: $ NASTRAN input file created by the MSC MSC/NASTRAN input file$ translator ( MSC/PATRAN Version 7.5 ) on January 16, 1998 at$ 08:27: OUTPUT2 = ‘2’, UNIT = 12$ Direct Text Input for File Management Section$ Nonlinear Static Analysis, DatabaseSOL 106TIME 600$ Direct Text Input for Executive ControlCENDSEALL = ALLSUPER = ALLTITLE = MSC/NASTRAN job created on 16-Jan-98 at 08:25:44ECHO = NONEMAXLINES = 999999999$ Direct Text Input for Global Case Control DataSUBCASE 1$ Subcase name : Default SUBTITLE=Default NLPARM = 1 SPC = 2 LOAD = 2 DISPLACEMENT(SORT1,REAL)=ALL FORCE(SORT1,REAL,BILIN)=ALL$ Direct Text Input for this SubcaseBEGIN BULKPARAM POST -1PARAM PATVER AUTOSPC NOPARAM COUPMASS -1PARAM K6ROT WTMASS LGDISP -1PARAM,NOCOMPS,-1PARAM PRTMAXIM YESNLPARM 1 4 AUTO 5 25 PW NO + A+ A .001 1.-7$ Direct Text Input for Bulk Data$ Elements and Element Properties for region : prop_1PROD 1 1 .01CROD 1 1 1 2$ Elements and Element Properties for region : prop_2PELAS 2 1 2 2 1 n 105 Exercise Workbook

WORKSHOP 32aSpring Element w/ Nonlin Params$ Referenced Material Records$ Material Record : mat_1$ Description of Material : Date: 19-Jun-97 Time: 15:12:40MAT1 1 1.+7$ Nodes of the Entire ModelGRID 1 0. 0. 2 0. 10. 0.$ Loads for Load Case : DefaultSPCADD 2 1 3LOAD 2 1. 1. 1$ Displacement Constraints of Load Set : constraint_1SPC1 1 123456 2$ Displacement Constraints of Load Set : constraint_2SPC1 3 23456 1$ Nodal Forces of Load Set : load_3FORCE 1 1 0 29000. 1. 0. 0.$ Referenced Coordinate FramesENDDATA n 105 Exercise Workbook32a-23

n 105 Exercise Workbook