{"id":381232,"date":"2024-08-30T21:11:56","date_gmt":"2024-08-30T21:11:56","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/mortar-contact-behavior-unaffected-by-igap\/"},"modified":"2024-08-30T21:11:56","modified_gmt":"2024-08-30T21:11:56","slug":"mortar-contact-behavior-unaffected-by-igap","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/mortar-contact-behavior-unaffected-by-igap\/","title":{"rendered":"Mortar contact behavior unaffected by IGAP"},"content":{"rendered":"<p>&lt;p&gt;Hi All,&lt;\/p&gt;&lt;p&gt;I&#8217;m currently setting up\/calibrating a model to represent nonlinear cyclic behavior of masonry in LS Dyna implicit. I am representing joints with *CONTACT_AUTOMATIC_SURFACE_TO_SURFACE_TIEBREAK_MORTAR_ID option.EQ.7. When I was tested the normal force-displacement behavior of the contact\/masonry assembly using a displacement controlled BPM, I observed some non-physical comressive behavior with significant penetrations of the contact interface. After reviewing the manual, I started tinkering with IGAP to reduce\/eliminate the penetrations. However, I am getting identical results regardless of the value I supply to IGAP. For my first run I specified IGAP.EQ.default. This was followed by values of 2 and 10. In all three cases the force and displacement are identical. I have attached a screenshot of my model, the comparative force displacement plot, and the contact definition. The SPC&#8217;s only restrain the z-direction, so there shouldn&#8217;t be any restraint against expansion. The BPM is z-direction only. The only connectivity between the two solid elements is the contact. The values for cards A&amp;B are the defaults as I left those blank on the input file.<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/08\/30-08-2024-1725052035-cyclic_normalDir_masonry.jpg\" alt=\"\" \/>&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/08\/30-08-2024-1725052050-contact_def.jpg\" alt=\"\" \/>&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/08\/30-08-2024-1725052110-normal-stress-displacement.png\" alt=\"\" \/>&lt;\/p&gt;&lt;p&gt;Does anyone have any suggestions of might be causing this?&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-381232","topic","type-topic","status-publish","hentry","topic-tag-contact","topic-tag-implicit-dynamics-1","topic-tag-masonry-1","topic-tag-tiebreak-1"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["348251"],"_bbp_author_ip":["2620:cc:8000:c22::bbc7"],"_btv_view_count":["488"],"_bbp_topic_status":["unanswered"],"_edit_lock":["1726066901:348251"],"_bbp_topic_id":["381232"],"_bbp_forum_id":["27814"],"_bbp_engagement":["348251"],"_bbp_voice_count":["1"],"_bbp_reply_count":["1"],"_bbp_last_reply_id":["382343"],"_bbp_last_active_id":["382343"],"_bbp_last_active_time":["2024-09-11 15:00:26"]},"test":"gcongdonbuffalo-edu"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/381232","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\/381232\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=381232"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}