{"id":254487,"date":"2021-07-21T15:06:33","date_gmt":"2021-07-21T15:06:33","guid":{"rendered":"\/forum\/forums\/topic\/nonlinear-material-model-causes-problems-in-aim-2020-r1\/"},"modified":"2023-04-06T10:13:45","modified_gmt":"2023-04-06T10:13:45","slug":"nonlinear-material-model-causes-problems-in-aim-2020-r1","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/nonlinear-material-model-causes-problems-in-aim-2020-r1\/","title":{"rendered":"Nonlinear material model causes problems in AIM 2020 R1"},"content":{"rendered":"<p><a class=\"wp-colorbox-image cboxElement\" href=\"\/forum\/wp-content\/uploads\/sites\/2\/discovery\/2021\/07\/288.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-248560\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/discovery\/2021\/07\/288.png\" alt=\"\" width=\"1720\" height=\"968\"><\/a> <a class=\"wp-colorbox-image cboxElement\" href=\"\/forum\/wp-content\/uploads\/sites\/2\/discovery\/2021\/07\/289.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-248562\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/discovery\/2021\/07\/289.png\" alt=\"\" width=\"1720\" height=\"968\"><\/a> <a class=\"wp-colorbox-image cboxElement\" href=\"\/forum\/wp-content\/uploads\/sites\/2\/discovery\/2021\/07\/290.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-248563\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/discovery\/2021\/07\/290.png\" alt=\"\" width=\"1720\" height=\"968\"><\/a> <a class=\"wp-colorbox-image cboxElement\" href=\"\/forum\/wp-content\/uploads\/sites\/2\/discovery\/2021\/07\/291.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-248564\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/discovery\/2021\/07\/291.png\" alt=\"\" width=\"1720\" height=\"1047\"><\/a> <a class=\"wp-colorbox-image cboxElement\" href=\"\/forum\/wp-content\/uploads\/sites\/2\/discovery\/2021\/07\/292.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-248565\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/discovery\/2021\/07\/292.png\" alt=\"\" width=\"1720\" height=\"1048\"><\/a> <a class=\"wp-colorbox-image cboxElement\" href=\"\/forum\/wp-content\/uploads\/sites\/2\/discovery\/2021\/07\/293.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-248566\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/discovery\/2021\/07\/293.png\" alt=\"\" width=\"1720\" height=\"1048\"><\/a> Hello everyone. I have a shell submodel to investigate a thin walled&nbsp;cold formed&nbsp;roof beam. I applied some displacements (calculated by another FEA software) on the purlin- and column ends (see attached figures 01-02-03). First, the Formulation of the displacements was set to &#8220;Rigid&#8221; and I ran the analysis with linear material model. Everything was fine with these settings, the displacements looked reasonable (see figure 04, deformation scaled 10x). If I switched to nonlinear material model (bilinear isotropic hardening), it caused the following problems: 1) <strong>Material model=Nonlinear; Displacement Formulation=Rigid:<\/strong> The calculation converged, no error messages, but the displacements are very strange (see figure 05, deformation scaled 10x) compared to linear material model results (figure 04, scaled 10x). It looks like AIM forgot the &#8220;Rigid&#8221; formulation setting on the purlin\/column ends if i switched to nonlinear material, and the applied displacements only deformed (not-rigidly) the purlin ends. 2) <strong>Material model=Nonlinear; Displacement Formulation=Program controled\/Deformable:<\/strong> I got a strange error message (see this post: <a href=\"\/forum\/forums\/topic\/strange-error-message-during-static-structural-analysis\/\" rev=\"auto\">Strange error message during static structural analysis<\/a> In addition, the convergence chart inside Solution Monitors tab looks like freezed nonetheless I can see that the last substep converged inside Transcript tab and the calculation completed. Phyisics branch shows &#8220;Partially Updated&#8221; results. If I evaluate these results I got the same strange displacements as in 1). I think the nonlinear material model causes these strange behaviors. Can you check these errors,&nbsp;please? I need results with nonlinear material model to check plastic strains. I attached three archive models, you can see the setting differences on the ends their file names. Thank you.<\/p>\n","protected":false},"template":"","class_list":["post-254487","topic","type-topic","status-closed","hentry","topic-tag-discovery-aim-2"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["29990"],"_bbp_likes_count":["0"],"_btv_view_count":["268"],"_edit_lock":["1680776003:2"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["254487"],"_bbp_forum_id":["27789"],"_bbp_engagement":["202","3452","29990"],"_bbp_voice_count":["3"],"_bbp_reply_count":["5"],"_bbp_last_reply_id":["260893"],"_bbp_last_active_id":["260893"],"_bbp_last_active_time":["2021-10-07 12:38:55"]},"test":"thornyaksteelxpert-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/254487","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\/254487\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=254487"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}