FINISH /CLEAR,START ! !* Comparison with 1D Bar solution (Mech Materials) ux(Lx)= P*Lx/(EA)=1. !* The question is: What about Plane Stress and Plane Strain models? !* Model used: !* P=pressure*A=pressure*1m2=200e9 E=200e9 (* Only linear elastic response *) !* Input values chosen to have ux=1 in the bar test !* Results: !* In case of PlaneStress with vv=0.3 in x=Lx ux=1 and uy=0.3 !* In case of PlaneStrain with vv=0.3 in x=Lx ux=0.91 and uy=0.39 !* In case of both cases with vv=0. in x=Lx ux=1 and uy=0 ! !* Obvious, because the bar in tension is under "plane stress" state !* Only Sxx and Syy=Szz=0 while Exx, Eyy and Ezz are <>0 !* In Plane strain the displacement have to be smaller due the deformation constraint Ezz=0 ! !* Ansys APDL macro * Copy all file to the command line (just click enter for default values) ! !/COM,ANSYS RELEASE Release 18.2 !/input,start,ans,'D:\Program Files\ANSYS Student\v182\ANSYS\apdl\' !* /PREP7 !* ET,1,PLANE182 !* !* Plane Stress IPState=0 + Plane Strain IPState=2 *ask, IPState, 'Enter Plane Stress IPState=0 + Plane Strain IPState=2 (def) ==>?',2 *if,IPState,EQ,0,THEN /TITLE,Plane Stress see lastline of PRNSOL (DMX is SUM) LX=LY=1 E=209GPa p=209e3MPa *elseif,IPState,EQ,2,THEN /TITLE,Plane Strain see lastline of PRNSOL (DMX is SUM) LX=LY=1 E=209GPa p=209e3MPa *ELSE /TITLE,IPState *ENDIF KEYOPT,1,1,0 KEYOPT,1,3,IPState KEYOPT,1,6,0 !* !* *ask, vv, 'Enter Poisson ratio vv (0 or 0.3 def)',0.3 MPTEMP,,,,,,,, MPTEMP,1,0 MPDATA,EX,1,,200e9 MPDATA,PRXY,1,,vv K,1,,,, K,2,1,,, K,3,1,1.,, K,4,0,1.,, LSTR, 1, 2 LSTR, 2, 3 LSTR, 3, 4 LSTR, 4, 1 AL,1,2,3,4 AATT, 1, , 1, 0, !* *ask, NELEMBYLINE, 'Enter Number of elements by line e.g. 1 (def)',1 !* LESIZE,ALL, , ,NELEMBYLINE, ,1, , ,1, MSHKEY,1 AMESH,ALL MSHKEY,0 !* DL,4, ,UX, DK,4, , , ,0,ALL, , , , , , ! SFL,2,PRES,-200e9, ! /DIST, 1 ,1.082226,1 /REP,FAST GPLOT ! FINISH /SOL /STATUS,SOLU SOLVE FINISH /POST1 PLDISP,1 !* /PSF,PRES,NORM,2,0,1 /PBF,DEFA, ,1 /PSYMB,CS,0 /PSYMB,NDIR,0 /PSYMB,ESYS,0 /PSYMB,LDIV,0 /PSYMB,LDIR,0 /PSYMB,ADIR,0 /PSYMB,ECON,0 /PSYMB,XNODE,0 /PSYMB,DOT,1 /PSYMB,PCONV, /PSYMB,LAYR,0 /PSYMB,FBCS,0 !* /PBC,ALL,,1 /PBC,NFOR,,0 /PBC,NMOM,,0 /PBC,RFOR,,0 /PBC,RMOM,,0 /PBC,PATH,,0 /REP !* !* PRNSOL,U,COMP