WS21-1 WORKSHOP 21 Thermal stress calculation from transient heat transfer run NAS104, Workshop 21, March 2004 Copyright 2004 MSC.Software Corporation. - презентация

1 WS21-1 WORKSHOP 21 Thermal stress calculation from transient heat transfer run NAS104, Workshop 21, March 2004 Copyright 2004 MSC.Software Corporation

2 WS21-2NAS104, Workshop 21, March 2004 Copyright 2004 MSC.Software Corporation

3 WS21-3NAS104, Workshop 21, March 2004 Copyright 2004 MSC.Software Corporation u Boundary conditions: u The h has unit of Btu/sec/in**2*degree F u Left Vertical edge has convection with h= to a hot ambient temperature at 2500 degrees u The right hand side(Free edges) is exposed to a convection boundary condition with h= to a cooled air temperature at 1000 degree u u Initial Temperature conditions: u u Initially the temperature is at 70 degree F u u The material properties are: u K=6.0e-4 Btu/sec/in/F u Cp=0.146 Btu/lbm.F u Mass density = Lbm/in**3 u u We want to run the analysis up to 2 seconds with constant time step of 0.1 sec. u u The NSTRAN test deck: h1_ct_2sec.dat u u The following is the temperature contour at time equal to 1.2 sec. Problem descriptions:

4 WS21-4NAS104, Workshop 21, March 2004 Copyright 2004 MSC.Software Corporation Temp for grid 31 and grid 70

5 WS21-5NAS104, Workshop 21, March 2004 Copyright 2004 MSC.Software Corporation Thermal stress calculation After the completion of the transient thermal analysis, we would like to perform a thermal stress calculation based on each 0.1 sec interval. The total analysis time is from 2 seconds, and thus we have 20 subcases in the linear static load case. We would like to constraint the model on the bottom edge along the vertical direction and constraint the left vertical edge along the horizontal direction.

6 WS21-6NAS104, Workshop 21, March 2004 Copyright 2004 MSC.Software Corporation Thermal stress at time equal to 1.9

7 WS21-7NAS104, Workshop 21, March 2004 Copyright 2004 MSC.Software Corporation Thermal stress from 20 subcases

8 WS21-8NAS104, Workshop 21, March 2004 Copyright 2004 MSC.Software Corporation We can see that the maximum stresses occur about time equal to 2.0 sec. It is interesting to note that the maximum thermal stress occurred way before the part had reached a steady state temperatures. The following is the NASTRAN input test deck:h1_coupled_z.dat First Model: Transient thermal analysis SOL 159 TIME 600 $ Direct Text Input for Executive Control CEND ANALYSIS = HEAT TITLE = MSC/NASTRAN job created on 22-Dec-99 at 09:49:55 ECHO = SORT MAXLINES = SPC = 1 IC = 1 $ Direct Text Input for Global Case Control Data SUBCASE 1 $ Subcase name : transient SUBTITLE=transient TSTEPNL = 1 THERMAL(SORT1,PRINT,punch)=ALL $ FLUX(SORT2,PRINT)=ALL $ Direct Text Input for this Subcase BEGIN BULK param,curvplot,1 PARAM,POST, 0

9 WS21-9NAS104, Workshop 21, March 2004 Copyright 2004 MSC.Software Corporation TSTEPNL,1, 20,.1, 1, ADAPT, 2, -10, PW,+ +,.001, 1.-6,,,,,,,+ +,,0 PSHELL,1, 1, 1. $ Pset: "shell" will be imported as: "pshell.1" CQUAD4, 1, 1, 1, 2, 7, 6 $And etc $ Material Record : thermal $ Description of Material : Date: 22-Dec-99 Time: 09:41:06 MAT4,1, 6.-4,.146,.283 $ Nodes of the Entire Model GRID,1,, 0., 0., 0. $And etc $ Loads for Load Case : transient $ Fixed Temperatures of Load Set : conv SPC,1, 71, 1, $ Fixed Temperatures of Load Set : conv_right SPC,1, 72, 1, $ Convection to Ambient of Load Set : conv PCONV, 1, 1001, 0, 0. CONV, , 1, 0, 0, 71 $ Convection to Ambient of Load Set : conv_right PCONV,2, 1002, 0, 0. CONV, , 2, 0, 0, 72 $ Initial Temperatures from Temperature Load Sets TEMP,1, 71, 2500., 72, $ Default Initial Temperature TEMPD,1, 70. $ CHBDYP Surface Elements and Element Properties CHBDYP, , 1, LINE,,, 6, 1,,+ +,,,,,-1.,0.0,0.0 PHBDY,1, 1. $ Free Convection Heat Transfer Coefficients MAT4,1001,,,, MAT4, 1002,,,, $ Scalar Points SPOINT,71, THRU, 72 $ Referenced Coordinate Frames ENDDATA d84163d3 Running with a time step of 0.1 sec, and with a total 20 timesteps.The adaptivity time stepping scheme is deactivated by setting ADJUST field equal to 0 on the TSTEPNL card

10 WS21-10NAS104, Workshop 21, March 2004 Copyright 2004 MSC.Software Corporation The Second model : Stress analysis using temperature results from the first run. The model file : include 'h1.model' SOL 101 TIME 600 $ Direct Text Input for Executive Control CEND SEALL = ALL SUPER = ALL TITLE = MSC/NASTRAN job created on 22-Dec-99 at 09:49:55 ECHO = NONE MAXLINES = $ Direct Text Input for Global Case Control Data TEMPERATURE(MATERIAL) = 1 SUBCASE 1 $ Subcase name : c1 SUBTITLE=c1 SPC = 2 TEMPERATURE(LOAD) = 1 DISPLACEMENT(SORT1,REAL)=ALL SPCFORCES(SORT1,REAL)=ALL STRESS(SORT1,REAL,VONMISES,BILIN)=ALL $ Direct Text Input for this Subcase SUBCASE 2 $ Subcase name : c2 SUBTITLE=c2 SPC = 2 TEMPERATURE(LOAD) = 2 DISPLACEMENT(SORT1,REAL)=ALL SPCFORCES(SORT1,REAL)=ALL STRESS(SORT1,REAL,VONMISES,BILIN)=ALL $AND ETC (Add SUBCASE 3 through 19 in between) SUBCASE 20 $ Subcase name : c20 SUBTITLE=c16 SPC = 2 TEMPERATURE(LOAD) =20 DISPLACEMENT(SORT1,REAL)=ALL SPCFORCES(SORT1,REAL)=ALL STRESS(SORT1,REAL,VONMISES,BILIN)=ALL Thermal stress (SOL 101) run

11 WS21-11NAS104, Workshop 21, March 2004 Copyright 2004 MSC.Software Corporation BEGIN BULK spoint,71,72 spc1,2,123456,71,72 PARAM,POST, 0 PARAM,PRTMAXIM,YES $ Referenced Material Records $ Material Record : structure $ Description of Material : Date: 22-Dec-99 Time: 09:41:06 MAT1, 1, 3.+7,.3,,, 1.-5 $ Nodes of the Entire Model $ Loads for Load Case : c1 SPCADD,2, 16, 18, 22 $ Displacement Constraints of Load Set : bottom SPC1, 16, 2456, 1, 2, 3, 4, 5 $ Displacement Constraints of Load Set : vertical SPC1, 18, 1456, 1, 6, 11, 16, 21, 26, + +, 31, 36, 41, 46 $ Constraint in Z direction spc1, 22, 3, 1 include 'h1_ct_2sec.pch' include 'h1.model' ENDDATA 1efaaec0

12 WS21-12NAS104, Workshop 21, March 2004 Copyright 2004 MSC.Software Corporation The following is a portion of the punch files: $TITLE = MSC/NASTRAN JOB CREATED ON 22-DEC-99 AT 09:49:55 76 $SUBTITLE=TRANSIENT 77 $LABEL = 78 $DISPLACEMENTS 79 $REAL OUTPUT 80 $SUBCASE ID = 1 81 $TIME = E TEMP* E TEMP* E TEMP* E TEMP* E TEMP* E TEMP* E TEMP* E TEMP* E TEMP* E TEMP* E TEMP* E TEMP* E TEMP* E TEMP* E TEMP* E TEMP* E TEMP* E TEMP* E TEMP* E TEMP* E TEMP* E TEMP* E TEMP* E TEMP* E TEMP* E TEMP* E TEMP* E TEMP* E TEMP* E Punch file from the first run