{"id":300979,"date":"2023-08-10T21:42:01","date_gmt":"2023-08-10T21:42:01","guid":{"rendered":"\/forum\/forums\/topic\/importing-compressional-test-data-for-hyperelastic-model-fitting\/"},"modified":"2023-08-10T21:42:01","modified_gmt":"2023-08-10T21:42:01","slug":"importing-compressional-test-data-for-hyperelastic-model-fitting","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/importing-compressional-test-data-for-hyperelastic-model-fitting\/","title":{"rendered":"Importing compressional test data for hyperelastic model fitting"},"content":{"rendered":"<p>Hi,<\/p>\n<p>I encountered some issue with fitting the compressional stress-strain curve using MAT_HYPERELASTIC (#077). I have defined both compressive stress and strain to be negative based on the general sign convention. When the calculation starts, warnings keeps popping up and MAT_HYPERELASTIC failed to read in my defined curve properly. Does LS-DYNA support compressive data fitting for hyperelastic materials?<\/p>\n<p>I have also tried to do the fitting my self and imput coefficient (C10, C20 &#8230;), but it ends up with 0 time step. (It cannot be solved by defining initial timesteps.) Is there any methods to resolve this issue?<\/p>\n<p>&nbsp;<\/p>\n<p>Thanks!<\/p>\n","protected":false},"template":"","class_list":["post-300979","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["184553","13468"],"_bbp_author_ip":["96.7.74.191"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["774"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["300979"],"_bbp_forum_id":["27814"],"_bbp_engagement":["13468","184553"],"_bbp_voice_count":["2"],"_bbp_reply_count":["2"],"_bbp_last_reply_id":["301750"],"_bbp_last_active_id":["301750"],"_bbp_last_active_time":["2023-08-16 18:06:40"]},"test":"hansenli"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/300979","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\/300979\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=300979"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}