{"id":456013,"date":"2026-04-08T10:46:47","date_gmt":"2026-04-08T10:46:47","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/czm-fracture-with-contact-debonding\/"},"modified":"2026-04-08T10:46:47","modified_gmt":"2026-04-08T10:46:47","slug":"czm-fracture-with-contact-debonding","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/czm-fracture-with-contact-debonding\/","title":{"rendered":"CZM fracture with Contact Debonding"},"content":{"rendered":"<p>&lt;p&gt;Hello everyone,&lt;\/p&gt;&lt;p&gt;I&rsquo;m a student working on a thesis project where I performed shear tests on bonded single-lap joints (SLJ). The tests produced a force&ndash;displacement curve, and my task is to reproduce this curve in ANSYS Mechanical using CZM fracture with Contact Debonding.&lt;\/p&gt;&lt;p&gt;I expected this to be relatively straightforward, but I&rsquo;m struggling to obtain a similar response. The simulated joint appears too stiff: the numerical force&ndash;displacement curve is much steeper than the experimental one.&lt;\/p&gt;&lt;p&gt;What I have tried so far: I am using fracture-energy-based debonding (CZM contact debonding). I ran a Taguchi\/DOE sweep with 24 combinations of: maximum normal\/tangential contact stress, and critical fracture energy for normal\/tangential separation\/slip.&lt;\/p&gt;&lt;p&gt;These parameters changed the failure behavior, but did not affect the initial curve(stiffness) of the curve.&lt;\/p&gt;&lt;p&gt;I also tried various contact stiffness adjustments, but these likewise did not significantly change the initial curve.&lt;\/p&gt;&lt;p&gt;Has anyone experienced this issue when simulating SLJ shear tests with CZM contact debonding?&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6037473\/uploads\/editor\/eu\/d8g47cjxuqdq.png\" \/>&lt;\/p&gt;&lt;p&gt;What settings or modeling choices typically control the initial stiffness in this type of model (e.g., cohesive stiffness\/penalty stiffness, bondline thickness, boundary conditions, machine\/grip compliance)?&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-456013","topic","type-topic","status-publish","hentry","topic-tag-contact-debonding","topic-tag-czm","topic-tag-fracture-mechanic-1","topic-tag-stiffness"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_forum_id":["27791"],"_bbp_topic_id":["456013"],"_bbp_author_ip":["134.238.139.246"],"_bbp_last_reply_id":["456064"],"_bbp_last_active_id":["456064"],"_bbp_last_active_time":["2026-04-08 17:13:50"],"_bbp_reply_count":["4"],"_bbp_reply_count_hidden":["0"],"_bbp_voice_count":["3"],"_bbp_engagement":["376253","58821","59239"],"_btv_view_count":["29"],"_bbp_topic_status":["unanswered"],"_bbp_subscription":["58821","59239","376253"]},"test":"marcin-praskiilot-lukasiewicz-gov-pl"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/456013","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\/456013\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=456013"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}