{"id":282240,"date":"2023-05-03T18:52:28","date_gmt":"2023-05-03T18:52:28","guid":{"rendered":"\/forum\/forums\/topic\/rigid-body-motion-in-static-structural-analysis\/"},"modified":"2023-05-03T18:52:28","modified_gmt":"2023-05-03T18:52:28","slug":"rigid-body-motion-in-static-structural-analysis","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/rigid-body-motion-in-static-structural-analysis\/","title":{"rendered":"Rigid body motion in static structural analysis"},"content":{"rendered":"<p>Hi,<\/p>\n<p>I&#8217;m having trouble eliminating rigid body motion in my analysis. The solver fails always at 17% progress. The model is of a quarter symmetric BGA where the PCB has a fixed support and the cut faces have frictionless supports assigned. The load is a thermal condition applied to all bodies. All contacts are bonded, except for three rough ones with the coating on top. Formulation for the bonded contacts is set to augmented lagrange and the stiffness is updated every iteration. Running the contact tool reports no open contacts, all are closed and look normal. I have weak springs enabled.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2023\/05\/03-05-2023-1683139655-problem_sim.png\" alt=\"\" width=\"854\" height=\"535\"><\/p>\n<p>The solver reports the following error:<\/p>\n<p>&nbsp;<\/p>\n<div id=\"paraDiv\">\n<p id=\"paragraphData\" class=\"paragraphText\" style=\"font-size: 12px;display: inline\">*** WARNING ***&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; CP =&nbsp;&nbsp;&nbsp; 3018.578&nbsp;&nbsp; TIME= 19:39:20<br \/>&nbsp;Material number 2519 (used by element 2005418) should normally have at&nbsp; <br \/>&nbsp;least one MP or one TB type command associated with it.&nbsp; Output of&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br \/>&nbsp;energy by material may not be available.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <\/p>\n<p>&nbsp;*** NOTE ***&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; CP =&nbsp;&nbsp;&nbsp; 3018.594&nbsp;&nbsp; TIME= 19:39:20<br \/>&nbsp;The step data was checked and warning messages were found.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br \/>&nbsp; Please review output or errors file (&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br \/>&nbsp;E:\\BGA_model\\_ProjectScratch\\Scr00BE\\file0.err ) for these warning&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br \/>&nbsp;messages.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <\/p>\n<p>&nbsp;*** NOTE ***&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; CP =&nbsp;&nbsp;&nbsp; 3018.594&nbsp;&nbsp; TIME= 19:39:20<br \/>&nbsp;This nonlinear analysis defaults to using the full Newton-Raphson&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br \/>&nbsp;solution procedure.&nbsp; This can be modified using the NROPT command.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <\/p>\n<\/div>\n<div id=\"paraDiv\">\n<p id=\"paragraphData\" class=\"paragraphText\" style=\"font-size: 12px;display: inline\">*** ERROR ***&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; CP =&nbsp;&nbsp;&nbsp; 3152.953&nbsp;&nbsp; TIME= 19:41:34<br \/>&nbsp;The value of UZ at node 957648 is 1.862045956E+11.&nbsp; It is greater than&nbsp; <br \/>&nbsp;the current limit of 1.E+09 (which can be reset on the NCNV command).&nbsp;&nbsp; <br \/>&nbsp;This generally indicates rigid body motion as a result of an&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br \/>&nbsp;unconstrained model.&nbsp; Verify that your model is properly constrained.&nbsp;&nbsp; <\/p>\n<p>&nbsp;*** ERROR ***&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; CP =&nbsp;&nbsp;&nbsp; 3152.953&nbsp;&nbsp; TIME= 19:41:34<br \/>&nbsp;*** MESSAGE CONTINUATION &#8212;- DIAGNOSTIC INFORMATION ***&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br \/>&nbsp;If one or more parts of the model are held together only by contact&nbsp;&nbsp;&nbsp;&nbsp; <br \/>&nbsp;verify that the contact surfaces are closed.&nbsp; You can check contact&nbsp;&nbsp;&nbsp;&nbsp; <br \/>&nbsp;status in the SOLUTION module for the converged solutions using&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br \/>&nbsp;CNCHECK.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <\/p>\n<p>&nbsp;*** WARNING ***&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; CP =&nbsp;&nbsp;&nbsp; 3152.953&nbsp;&nbsp; TIME= 19:41:34<br \/>&nbsp;The unconverged solution (identified as time 1800 substep 999999) is&nbsp;&nbsp;&nbsp; <br \/>&nbsp;output for analysis debug purposes.&nbsp; Results should not be used for&nbsp;&nbsp;&nbsp;&nbsp; <br \/>&nbsp;any other purpose.&nbsp;&nbsp;&nbsp;<\/p>\n<p class=\"paragraphText\" style=\"font-size: 12px;display: inline\">&nbsp;<\/p>\n<p class=\"paragraphText\" style=\"font-size: 12px;display: inline\">&nbsp;<\/p>\n<p class=\"paragraphText\" style=\"font-size: 12px;display: inline\"><span style=\"font-size: 14pt\">Thanks in advance.<\/span><\/p>\n<p class=\"paragraphText\" style=\"font-size: 12px;display: inline\">&nbsp;<\/p>\n<p class=\"paragraphText\" style=\"font-size: 12px;display: inline\"><span style=\"font-size: 14pt\">Frederik<\/span><\/p>\n<\/div>\n","protected":false},"template":"","class_list":["post-282240","topic","type-topic","status-closed","hentry","topic-tag-mechanicalworkbench-1","topic-tag-ansysmechanical","topic-tag-mechanical"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["283991","88"],"_bbp_author_ip":["168.143.243.24"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["2861"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["282240"],"_bbp_forum_id":["27791"],"_bbp_engagement":["88","283991"],"_bbp_voice_count":["2"],"_bbp_reply_count":["6"],"_bbp_last_reply_id":["283013"],"_bbp_last_active_id":["283013"],"_bbp_last_active_time":["2023-05-09 11:07:51"]},"test":"frederik-zemlindanfoss-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/282240","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\/282240\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=282240"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}