{"id":426497,"date":"2025-03-21T19:39:17","date_gmt":"2025-03-21T19:39:17","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/apdl-code-to-apply-a-skin-of-shell181-elements-on-some-areas-of-a-volume-mesh\/"},"modified":"2025-03-21T19:39:17","modified_gmt":"2025-03-21T19:39:17","slug":"apdl-code-to-apply-a-skin-of-shell181-elements-on-some-areas-of-a-volume-mesh","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/apdl-code-to-apply-a-skin-of-shell181-elements-on-some-areas-of-a-volume-mesh\/","title":{"rendered":"APDL code to apply a skin of SHELL181 elements on some AREAs of a VOLUME mesh"},"content":{"rendered":"

<p>I am just starting to learn MAPDL. Hopefully this is a simple question.<\/p><p>In MAPDL a volume was created using BLOCK. A mesh of CPT215 hex elements were created by VSWEEP between two AREA IDs of that volume using MATID 1.  I create a mesh of SHELL181 elements on 3 AREAs of that volume and am trying to use MATID 4 for those to change from a porous material to a non-porous hyperelastic material.  I have some APDL code below to look at. When I read this file into Mechanical APDL, I get an error. Shell element 1063 does not have a valid section ID or real constants. <\/p><p>This is a follow-on question to this discussion: https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/pore-pressure-analysis-with-cpt215-elements-porous-elasticity-and-pm\/<\/a><\/p><\/p>\n

finish<br>\/clear<br>! units of mm kg and N<br>\/TITLE, PorousElastic_PM_Skin<br>\/prep7<br>ET,1,CPT215<br>keyopt,1,12,1<br>TB,PELAS,1,1,,POISSON<br>TBDATA,1,0.1,10,0.1,0.45<br>FPX=0.1e-2<br>TB,PM,1,,,PERM<br>TBDATA,1,FPX<br>ETABLE,p_pres,PMSV,PPRE<br>! create and mesh geometry<br>block,,80,,20,,6<br>cyl4,20,,6,,,,6<br>cyl4,60,,6,,,,6<br>vsbv,1,all<br>VSEL,ALL<br>MSHAPE,0,3D<br>ESIZE,2<br>VSWEEP,4,18<br>! Define a new material and create a skin of elements on 3 faces of the volume.<br>TB,HYPE,4,1,1,NEO <br>TBDATA,1,0.003,50000000<br>ET,4,SHELL181<br>keyop,4,1,1         ! Membrane stiffness only<br>SECTYPE,4,SHELL ! Define shell section<br>SECDATA,1.0,4 ! Define section data, THICKNESS, MATID<br>ASEL,S,AREA,,4,6,1<br>AMESH,ALL,<br>esel,all<br>! apply symmetry BCs<br>nsel,s,loc,y,0<br>d,all,uy<br>nsel,s,loc,z,0<br>d,all,uz<br>! fix one node in x<br>nsel,r,loc,y,0<br>nsel,r,loc,x,0<br>d,all,ux<br>! apply pressure loads to areas 9 and 13<br>pp_inlet=1.1<br>pp_outlet=1.0<br>SFA,9,1,PRES,pp_inlet<br>SFA,13,1,PRES,pp_outlet<br>finish<br>\/solu<br>antype,0             ! static analysis<br>nlgeom,on            ! Turn on Large Deformation<br>eqsl,sparse,,,,,1<br>solve<br>autots,on            ! Turn on auto time stepping<br>nsub,20,1000,10,OFF<br>time,1.<br>finish<br>!\/view,1,1,2,3<br>!\/expand,1,rect,half,0,0,-1e-6<br>!\/expand,2,rect,half,0,-1e-6,0,2,rect,half,0,0,-1e-6<br>\/post1<br>set,last<br>!plesol,s,eqv<br>esel,all<br>ETABLE,p_pres,PMSV,PPRE<br>ETABLE,f_flux_x,FFLX,X<br>ETABLE,f_flux_y,FFLX,Y<br>ETABLE,f_flux_z,FFLX,<\/pre>\n","protected":false},"template":"","class_list":["post-426497","topic","type-topic","status-publish","hentry"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t