{"id":442995,"date":"2025-10-03T19:14:34","date_gmt":"2025-10-03T19:14:34","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/help-to-validate-plastic-deformation\/"},"modified":"2025-10-03T19:14:34","modified_gmt":"2025-10-03T19:14:34","slug":"help-to-validate-plastic-deformation","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/help-to-validate-plastic-deformation\/","title":{"rendered":"Help to validate Plastic deformation"},"content":{"rendered":"<p>&lt;p&gt;Hello,&nbsp;&lt;\/p&gt;&lt;p&gt;I have a drop-impact simulation of a Glass+Plastic (polycarbonate) assembly. I&#8217;m get results that look like the Polycarbonate is undergoing plastic deformation.&lt;\/p&gt;&lt;p&gt;However, I have limited experience validating plastic deformation in LS-DYNA and would like some help on this. I&#8217;m especially worried if i&#8217;ve artificially introduced some non-physical plastic deformation in my attempts to eliminate Hourglass energy.&nbsp;&lt;\/p&gt;&lt;p&gt;&lt;span style=&#8221;text-decoration: underline;&#8221;&gt;Setup:&lt;\/span&gt;&lt;\/p&gt;<\/p>\n<ul>\n<li>Materials: Glass &#8211; Proprietary (substrate) , Plastic, PC High viscosity &#8211; Ansys default library (around the glass perimeter) , Steel &#8211; Default library(rigid body- shell)&nbsp;<\/li>\n<li>Contacts:\n<ul>\n<li>Glass &lt;-&gt; PC : Shared topology<\/li>\n<li>PC &lt;-&gt; Plate : Frictional\n<ul>\n<li>Behavior: Asymmetric<\/li>\n<li>Formulation: Pure Penalty (Automatic_nodes_to_surface)<\/li>\n<li>Viscous damping coefficient: 0.1<\/li>\n<li>Contact \/ Target Penalty Scale Factors: 10&nbsp;<\/li>\n<li>Soft Constraint Formulations: Segment Based<\/li>\n<li>Soft constraint Scale Factor: 1<\/li>\n<li>Depth: 2<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<li>Mesh: Hex8 (for glass, PC), and Quad4 (plate)<\/li>\n<li>Hourglass controls:&nbsp;\n<ul>\n<li>PC: ID 7 (Belytschko-Bindeman Linear Total Strain), coefficient = 1<\/li>\n<\/ul>\n<\/li>\n<li>Element Controls:\n<ul>\n<li>PC: Fully Integrated S\/R Solid<\/li>\n<\/ul>\n<\/li>\n<li>Analysis setting:\n<ul>\n<li>Global Hourglass control: ID 5 (Exact Volume Flanagam-Belytschko Stiffness Form), coefficient = 0.1<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>&lt;p&gt;Points to note \/ Concerns:&nbsp;&lt;\/p&gt;<\/p>\n<ul>\n<li>High distortion of the PC (not sure how I can check this is actually physical\/ potential mesh issue)<\/li>\n<li>The contact energy increases and stays high (I think this is ok since there&#8217;s sliding at the frictional interface)<\/li>\n<li>Internal energy stays high after impact (again, I think this is physical since there&#8217;s work done on the PC layer)<\/li>\n<\/ul>\n<p>&lt;p&gt;&lt;br&gt;<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2025\/10\/03-10-2025-1759512237-mceclip0.png\" width=\"634\" height=\"277\" \/>&lt;\/p&gt;&lt;p&gt;<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2025\/10\/03-10-2025-1759511979-LSDyna_Impact_plastic.gif\" alt=\"\" width=\"546\" height=\"208\" \/><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2025\/10\/03-10-2025-1759513908-mceclip1.png\" width=\"407\" height=\"228\" \/>&lt;\/p&gt;&lt;p&gt;<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2025\/10\/03-10-2025-1759518789-mceclip2.png\" width=\"746\" height=\"289\" \/>&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-442995","topic","type-topic","status-publish","hentry","topic-tag-hourglass-energy","topic-tag-impact-analysis","topic-tag-impacttest-1","topic-tag-lsdyna","topic-tag-plastic-deformation-1"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_forum_id":["27814"],"_bbp_topic_id":["442995"],"_bbp_subscription":["295055","480261"],"_bbp_author_ip":["199.19.248.85"],"_bbp_last_reply_id":["443048"],"_bbp_last_active_id":["443048"],"_bbp_last_active_time":["2025-10-05 18:03:41"],"_bbp_reply_count":["1"],"_bbp_reply_count_hidden":["0"],"_bbp_voice_count":["2"],"_bbp_engagement":["295055","480261"],"_btv_view_count":["308"],"_bbp_topic_status":["unanswered"]},"test":"shrihari_sampathkumaramat-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/442995","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\/442995\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=442995"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}