


{"id":45340,"date":"2020-06-21T19:58:57","date_gmt":"2020-06-21T19:58:57","guid":{"rendered":"\/forum\/forums\/topic\/solver-pivot-errors\/"},"modified":"2020-06-21T19:58:57","modified_gmt":"2020-06-21T19:58:57","slug":"solver-pivot-errors","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/solver-pivot-errors\/","title":{"rendered":"Solver pivot errors"},"content":{"rendered":"<p>Hello.&nbsp;<\/p>\n<p><\/p>\n<p>I am working on a static structural project, and it appears that the solver won&#8217;t work due to the pivot errors.&nbsp;<\/p>\n<p><\/p>\n<p>One of the errors goes: Solver pivot warnings or errors have been encountered during the solution.&nbsp; This is usually a result of an ill conditioned matrix possibly due to unreasonable material properties, an under constrained model, or contact related issues.&nbsp; Check results carefully.<\/p>\n<p><\/p>\n<p>And the another goes: A solver pivot warning or error has been detected in the UZ degree of freedom of node 1460 located in Solid. This is usually a result of an ill conditioned matrix possibly due to unreasonable material properties, an under constrained model, or contact related issues.&nbsp; Check results carefully. You may select the offending object and\/or geometry via RMB on this warning in the Messages window.<\/p>\n<p><\/p>\n<p>&nbsp;<\/p>\n<p><\/p>\n<p>I have uploaded the file, so please take a look.<\/p>\n<p><\/p>\n<p>What I&#8217;m focusing on at the moment is &#8220;B&#8221; system, where &#8220;A&#8221; system contains a slight geometric modification from &#8220;B&#8221;. The errors appear in both systems, so those modifications do not seem to be the reasons.<\/p>\n<p><\/p>\n<p>Force is acted on a single (fixed) point&nbsp;of the structure that somewhat resembles a cup we use for drinking, and the entire structure theoretically shares the direction of the displacement. The last part of the boundary condition is represented in the displacement section.<\/p>\n<p><\/p>\n<p>The error messages suggest few ideas,&nbsp;and the only&nbsp;suggestion probable is the one about the&nbsp;underconstrained model. Material property does not seem to be problematic, and there is no contact at all. Possibility of this being an underconstrained model is considered in system &#8220;C&#8221;, where the scope of the&nbsp;constant displacement is the entire structure. &#8220;C&#8221; does not give out any errors, but the solution&nbsp;for the Equivalent stress is zero everywhere, which I intuitively declare untrue.<\/p>\n<p><\/p>\n<p>Please let me know if you understand what is the problem with &#8220;B&#8221; or &#8220;C&#8217;. Thank you for answering.<\/p>\n","protected":false},"template":"","class_list":["post-45340","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["17521"],"_bbp_old_topic_author_name_id":["Anonymous"],"_bbp_old_is_topic_anonymous_id":["false"],"_bbp_old_closed_status_id":["publish"],"_bbp_author_ip":[null],"_bbp_old_sticky_status_id":["normal"],"_bbp_likes_count":["0"],"_btv_view_count":["1483"],"_bbp_subscription":["252898"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["45340"],"_bbp_forum_id":["27791"],"_bbp_engagement":["79","178776"],"_bbp_voice_count":["2"],"_bbp_reply_count":["1"],"_bbp_last_reply_id":["118564"],"_bbp_last_active_id":["118564"],"_bbp_last_active_time":["2020-06-22 15:24:06"]},"test":"seol7281"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/45340","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\/45340\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=45340"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}