{"id":413015,"date":"2025-02-11T13:43:30","date_gmt":"2025-02-11T13:43:30","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/frictionless-contact-separation-problem\/"},"modified":"2025-02-12T16:57:57","modified_gmt":"2025-02-12T16:57:57","slug":"frictionless-contact-separation-problem","status":"answered","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/frictionless-contact-separation-problem\/","title":{"rendered":"Frictionless contact &#8211; separation problem"},"content":{"rendered":"<p>&lt;p&gt;&lt;p&gt;Hello,&lt;\/p&gt;&lt;p&gt;I am modeling a testing setup in which the facesheet of a sandwich beam is peeled off the core, separating it from the core by a fair amount. In the first figure the solution of a static structural analysis can be seen, which I conducted for the purpose of testing the contacts and boundary conditions.&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2025\/02\/11-02-2025-1739281301-Deflection_iso.PNG\" alt=\"\" \/>&lt;br&gt;&lt;br&gt;However, when I attempt a modal analysis, the first mode shows a bending oscillation in the upper rod, resulting in considerable penetration between the delaminated part of the facesheet and the core (figure 2). That makes sense, since I did not define any contact between this part of the facesheet and the core.&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2025\/02\/11-02-2025-1739281355-Penetration_no_contact.PNG\" alt=\"\" \/>&lt;br&gt;&lt;br&gt;If I define a <em>frictionless<\/em> contact between them, though, the solution does not converge. Moreover, the result of the static structural analysis shows then only minimal separation between the bodies, which is not realistic.&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2025\/02\/11-02-2025-1739281387-Separation_frictionless_contact.PNG\" alt=\"\" \/>&lt;\/p&gt;&lt;p&gt;How do I deal with this problem and what other options do I have other than <em>frictionless<\/em> contact, to allow for separation, but not for penetration?&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;&lt;p&gt;Thanks in advance and best regards,&lt;\/p&gt;&lt;p&gt;Nikita&lt;\/p&gt;&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-413015","topic","type-topic","status-answered","hentry","topic-tag-contact","topic-tag-frictionless","topic-tag-frictionless-contact-1","topic-tag-no-separation-1","topic-tag-non-penetrationcontact-1"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_forum_id":["27791"],"_bbp_topic_id":["413015"],"_bbp_author_ip":["149.205.90.124"],"_bbp_last_reply_id":["419173"],"_bbp_last_active_id":["419173"],"_bbp_last_active_time":["2025-02-12 16:57:48"],"_bbp_reply_count":["2"],"_bbp_reply_count_hidden":["0"],"_bbp_voice_count":["2"],"_btv_view_count":["250"],"_bbp_topic_status":["answered"],"_bbp_engagement":["423167","276552"],"_edit_last":["423167"],"_bbp_revision_log":["a:1:{i:413018;a:2:{s:6:\"author\";i:423167;s:6:\"reason\";s:0:\"\";}}"],"_bbp_subscription":["276552","423167"]},"test":"nikita-falkegmx-net"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/413015","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":1,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/413015\/revisions"}],"predecessor-version":[{"id":413018,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/413015\/revisions\/413018"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=413015"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}