{"id":293083,"date":"2023-07-14T09:31:47","date_gmt":"2023-07-14T09:31:47","guid":{"rendered":"\/forum\/?post_type=topic&#038;p=293083"},"modified":"2023-07-14T09:31:47","modified_gmt":"2023-07-14T09:31:47","slug":"negative-jacobian-fail","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/negative-jacobian-fail\/","title":{"rendered":"Negative Jacobian \u2013 Fail"},"content":{"rendered":"<p class=\"MsoNormal\"><span style=\"font-family: Tahoma, sans-serif;font-size: 12pt\">Can you please advice me any further steps to overcome negative Jacobian fail? The following steps were tried to handle.<\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-family: Tahoma, sans-serif;font-size: 12pt\">The soft body impact FE model configured using SPH impactor and shell (UD facing and backing skins) &amp; solid (honeycomb core) elements of a wing. The UD elements are formed using *MAT54\/55 (Enhanced damage).<\/span><\/p>\n<ul type=\"disc\">\n<li class=\"MsoListParagraph\"><span style=\"font-size: 12pt;font-family: Tahoma, sans-serif\">ELFORM changed to reduce integration.&nbsp;<\/span><span style=\"font-size: 12pt\">Shell element formulation is converted to 2 from 16 to reduce number of integration points when I got the negative Jacobian fail (The termination rows are added to this message). *SECTION_SHELL cards are deleted after creation of *PART_COMPOSITE. Then, the section is changed on this card.<\/span><\/li>\n<li class=\"MsoListParagraph\"><span style=\"font-size: 12pt;font-family: Tahoma, sans-serif\">Hourglassing formulation type &amp; parameter<\/span><\/li>\n<li class=\"MsoListParagraph\"><span style=\"font-size: 12pt;font-family: Tahoma, sans-serif\">Number of plies increased<\/span><\/li>\n<li class=\"MsoListParagraph\"><span style=\"font-size: 12pt;font-family: Tahoma, sans-serif\">TFAIL, DFAILM, DFAILS, EFS parameters<\/span><\/li>\n<li class=\"MsoListParagraph\"><span style=\"font-size: 12pt;font-family: Tahoma, sans-serif\">Model clean-up<\/span><\/li>\n<li class=\"MsoListParagraph\"><span style=\"font-size: 12pt;font-family: Tahoma, sans-serif\">Decreasing timestep &amp; remove mass scaling<\/span><\/li>\n<li class=\"MsoListParagraph\"><span style=\"font-size: 12pt\">Solver: 2022 R1<\/span><\/li>\n<\/ul>\n<p class=\"MsoNormal\"><span style=\"font-size: 11.0pt\">Unit system: [t,mm,N,s]<\/span><\/p>\n<p><span style=\"font-size: 12pt;font-family: Tahoma, sans-serif\"><img decoding=\"async\" title=\"FE Model\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2023\/07\/14-07-2023-1689326322-NJ_Fail_230713_2.JPG\" alt=\"FE Model\"><\/span><\/p>\n<div><span style=\"font-size: 10pt\">SHELL ELEMENT QUALITY CHECK SUMMARY:<\/span><\/div>\n<div><em><span style=\"font-size: 10pt\">&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8211;<\/span><\/em><\/div>\n<div><em><span style=\"font-size: 10pt\">Quality Name&nbsp; &nbsp; &nbsp; &nbsp; Min. val&nbsp; &nbsp; &nbsp; &nbsp;Max. val&nbsp; &nbsp; &nbsp; &nbsp;Allowable&nbsp; &nbsp; #Violated(%)<\/span><\/em><\/div>\n<div><em><span style=\"font-size: 10pt\">&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8211;<\/span><\/em><\/div>\n<div><em><span style=\"font-size: 10pt\">Min side length&nbsp; &nbsp; &nbsp;4.12&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;5.44&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;3&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 0(0%)<\/span><\/em><\/div>\n<div><em><span style=\"font-size: 10pt\">Max side length&nbsp; &nbsp; &nbsp;4.77&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;8.5&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 30&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;0(0%)<\/span><\/em><\/div>\n<div><em><span style=\"font-size: 10pt\">Aspect Ratio&nbsp; &nbsp; &nbsp; &nbsp; 1&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 1.85&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;10&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;0(0%)<\/span><\/em><\/div>\n<div><em><span style=\"font-size: 10pt\">Warpage&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;0&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 0.128&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 10&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;0(0%)<\/span><\/em><\/div>\n<div><em><span style=\"font-size: 10pt\">Min Quad Angle&nbsp; &nbsp; &nbsp; 88.3&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;90&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;45&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;0(0%)<\/span><\/em><\/div>\n<div><em><span style=\"font-size: 10pt\">Max Quad Angle&nbsp; &nbsp; &nbsp; 90&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;91.7&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;135&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 0(0%)<\/span><\/em><\/div>\n<div><em><span style=\"font-size: 10pt\">Min Tria Angle&nbsp; &nbsp; &nbsp; 0&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 0&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 30&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;0(0%)<\/span><\/em><\/div>\n<div><em><span style=\"font-size: 10pt\">Max Tria Angle&nbsp; &nbsp; &nbsp; 0&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 0&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 120&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 0(0%)<\/span><\/em><\/div>\n<div><em><span style=\"font-size: 10pt\">Taper&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;0&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 0.0143&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;0.7&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 0(0%)<\/span><\/em><\/div>\n<div><em><span style=\"font-size: 10pt\">Skew&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 0&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 1.27&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;45&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;0(0%)<\/span><\/em><\/div>\n<div><em><span style=\"font-size: 10pt\">Jacobian&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 0.911&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 1&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 0.6&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 0(0%)<\/span><\/em><\/div>\n<div><em><span style=\"font-size: 10pt\">Char. length&nbsp; &nbsp; &nbsp; &nbsp; 4.12&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;5.46&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;1&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 0(0%)<\/span><\/em><\/div>\n<div><em><span style=\"font-size: 10pt\">Area&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 20.6&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;45.6&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;5&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 0(0%)<\/span><\/em><\/div>\n<div><em><span style=\"font-size: 10pt\">Feature angle&nbsp; &nbsp; &nbsp; &nbsp;0&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 85&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;30&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;8192(4.55%)<\/span><\/em><\/div>\n<div><em><span style=\"font-size: 10pt\">TimeStep&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 3.98e-07&nbsp; &nbsp; &nbsp; &nbsp;5.26e-07&nbsp; &nbsp; &nbsp; &nbsp;1e-07&nbsp; &nbsp; &nbsp; &nbsp; 0(0%)<\/span><\/em><\/div>\n<div><em><span style=\"font-size: 10pt\">&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8211;<\/span><\/em><\/div>\n<div><em><span style=\"font-size: 10pt\">#QUADS(%):180224(100%), #TRIAS(%):0(0%), #TOTAL OF FAILED(%):8192(4.55%)<\/span><\/em><\/div>\n<div><em><span style=\"font-size: 10pt\">&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8211;<\/span><\/em><\/div>\n<p><span style=\"font-size: 12pt;font-family: Tahoma, sans-serif\">Fail message from .d3hsp file:<\/span><\/p>\n<p><span style=\"font-size: 10pt\"><em><span style=\"font-family: Tahoma, sans-serif\">&nbsp;*** Warning 40098 (SOL+98)<br \/>&nbsp; &nbsp; &nbsp;ALE time step size is less than dt2ms at cycle 20<br \/>&nbsp; &nbsp; &nbsp;Mass scaling time step size of<br \/>&nbsp; &nbsp; &nbsp;element id: 456411 has a dt: 5.8372E-07<br \/>&nbsp; &nbsp; &nbsp;element id: 350107 has a dt: 5.8372E-07<br \/>&nbsp; &nbsp; &nbsp;element id: 354939 has a dt: 5.8372E-07<br \/>&nbsp; &nbsp; &nbsp;element id: 359771 has a dt: 5.8372E-07<br \/>&nbsp; &nbsp; &nbsp;element id: 369435 has a dt: 5.8372E-07<br \/>&nbsp; &nbsp; &nbsp;element id: 374267 has a dt: 5.8372E-07<br \/>&nbsp; &nbsp; &nbsp;element id: 379099 has a dt: 5.8372E-07<br \/>&nbsp; &nbsp; &nbsp;element id: 388763 has a dt: 5.8372E-07<br \/>&nbsp; &nbsp; &nbsp;element id: 393595 has a dt: 5.8372E-07<br \/>&nbsp; &nbsp; &nbsp;element id: 398427 has a dt: 5.8372E-07<br \/>&nbsp;<br \/>&nbsp;*** Warning 40101 (SOL+101)<br \/>&nbsp; &nbsp; &nbsp;ALE time step size is less than dt2ms.<br \/>&nbsp; &nbsp; &nbsp;Further output has been suppressed beyond cycle 21<br \/>&nbsp;f a i l e d &nbsp; e l e m e n t &nbsp; r e p o r t &nbsp;time= &nbsp;1.1307E-05<br \/>&nbsp; &nbsp; &nbsp;number of failed solid &nbsp;elements = 0<br \/>&nbsp; &nbsp; &nbsp;number of failed beam &nbsp; elements = 0<br \/>&nbsp; &nbsp; &nbsp;number of failed shell &nbsp;elements = 1<br \/>&nbsp; &nbsp; &nbsp;number of failed tshell elements = 0<br \/>&nbsp; &nbsp; &nbsp;shell element 782030 &nbsp;failed at time &nbsp;1.1307E-05<\/span><\/em><\/span><\/p>\n<p><span style=\"font-size: 12pt;font-family: Tahoma, sans-serif\">Regards,<\/span><\/p>\n","protected":false},"template":"","class_list":["post-293083","topic","type-topic","status-closed","hentry","topic-tag-explicit","topic-tag-lsdyna"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_author_ip":["23.217.200.46"],"_bbp_subscription":["48610","181804"],"_btv_view_count":["2637"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["293083"],"_bbp_forum_id":["27814"],"_bbp_engagement":["48610","181804"],"_bbp_voice_count":["2"],"_bbp_reply_count":["2"],"_bbp_last_reply_id":["293339"],"_bbp_last_active_id":["293339"],"_bbp_last_active_time":["2023-07-17 08:43:41"]},"test":"ekayar01qub-ac-uk"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/293083","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\/293083\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=293083"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}