{"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>&lt;p&gt;I am just starting to learn MAPDL. Hopefully this is a simple question.&lt;\/p&gt;&lt;p&gt;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.&nbsp; 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.&nbsp; 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.&nbsp;&lt;\/p&gt;&lt;p&gt;This is a follow-on question to this discussion:&nbsp;<a href=\"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/pore-pressure-analysis-with-cpt215-elements-porous-elasticity-and-pm\/\">https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/pore-pressure-analysis-with-cpt215-elements-porous-elasticity-and-pm\/<\/a>&lt;\/p&gt;<\/p>\n<pre>finish&lt;br&gt;\/clear&lt;br&gt;! units of mm kg and N&lt;br&gt;\/TITLE, PorousElastic_PM_Skin&lt;br&gt;\/prep7&lt;br&gt;ET,1,CPT215&lt;br&gt;keyopt,1,12,1&lt;br&gt;TB,PELAS,1,1,,POISSON&lt;br&gt;TBDATA,1,0.1,10,0.1,0.45&lt;br&gt;FPX=0.1e-2&lt;br&gt;TB,PM,1,,,PERM&lt;br&gt;TBDATA,1,FPX&lt;br&gt;ETABLE,p_pres,PMSV,PPRE&lt;br&gt;! create and mesh geometry&lt;br&gt;block,,80,,20,,6&lt;br&gt;cyl4,20,,6,,,,6&lt;br&gt;cyl4,60,,6,,,,6&lt;br&gt;vsbv,1,all&lt;br&gt;VSEL,ALL&lt;br&gt;MSHAPE,0,3D&lt;br&gt;ESIZE,2&lt;br&gt;VSWEEP,4,18&lt;br&gt;! Define a new material and create a skin of elements on 3 faces of the volume.&lt;br&gt;TB,HYPE,4,1,1,NEO&nbsp;&lt;br&gt;TBDATA,1,0.003,50000000&lt;br&gt;ET,4,SHELL181&lt;br&gt;keyop,4,1,1 &nbsp; &nbsp; &nbsp; &nbsp; ! Membrane stiffness only&lt;br&gt;SECTYPE,4,SHELL ! Define shell section&lt;br&gt;SECDATA,1.0,4 ! Define section data, THICKNESS, MATID&lt;br&gt;ASEL,S,AREA,,4,6,1&lt;br&gt;AMESH,ALL,&lt;br&gt;esel,all&lt;br&gt;! apply symmetry BCs&lt;br&gt;nsel,s,loc,y,0&lt;br&gt;d,all,uy&lt;br&gt;nsel,s,loc,z,0&lt;br&gt;d,all,uz&lt;br&gt;! fix one node in x&lt;br&gt;nsel,r,loc,y,0&lt;br&gt;nsel,r,loc,x,0&lt;br&gt;d,all,ux&lt;br&gt;! apply pressure loads to areas 9 and 13&lt;br&gt;pp_inlet=1.1&lt;br&gt;pp_outlet=1.0&lt;br&gt;SFA,9,1,PRES,pp_inlet&lt;br&gt;SFA,13,1,PRES,pp_outlet&lt;br&gt;finish&lt;br&gt;\/solu&lt;br&gt;antype,0 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; ! static analysis&lt;br&gt;nlgeom,on &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;! Turn on Large Deformation&lt;br&gt;eqsl,sparse,,,,,1&lt;br&gt;solve&lt;br&gt;autots,on &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;! Turn on auto time stepping&lt;br&gt;nsub,20,1000,10,OFF&lt;br&gt;time,1.&lt;br&gt;finish&lt;br&gt;!\/view,1,1,2,3&lt;br&gt;!\/expand,1,rect,half,0,0,-1e-6&lt;br&gt;!\/expand,2,rect,half,0,-1e-6,0,2,rect,half,0,0,-1e-6&lt;br&gt;\/post1&lt;br&gt;set,last&lt;br&gt;!plesol,s,eqv&lt;br&gt;esel,all&lt;br&gt;ETABLE,p_pres,PMSV,PPRE&lt;br&gt;ETABLE,f_flux_x,FFLX,X&lt;br&gt;ETABLE,f_flux_y,FFLX,Y&lt;br&gt;ETABLE,f_flux_z,FFLX,<\/pre>\n","protected":false},"template":"","class_list":["post-426497","topic","type-topic","status-publish","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_forum_id":["27791"],"_bbp_topic_id":["426497"],"_bbp_subscription":["240","20905"],"_bbp_author_ip":["8.9.83.120"],"_bbp_last_reply_id":["426820"],"_bbp_last_active_id":["426820"],"_bbp_last_active_time":["2025-03-25 15:35:52"],"_bbp_reply_count":["4"],"_bbp_reply_count_hidden":["0"],"_bbp_voice_count":["2"],"_bbp_engagement":["240","20905"],"_btv_view_count":["357"],"_bbp_topic_status":["unanswered"]},"test":"peteroznewman"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/426497","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics"}],"about":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/types\/topic"}],"version-history":[{"count":0,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/426497\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=426497"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}