{"id":449899,"date":"2026-01-07T10:44:41","date_gmt":"2026-01-07T10:44:41","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/problem-with-displacement-condition\/"},"modified":"2026-01-07T10:44:41","modified_gmt":"2026-01-07T10:44:41","slug":"problem-with-displacement-condition","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/problem-with-displacement-condition\/","title":{"rendered":"Problem with displacement condition"},"content":{"rendered":"<p>&lt;p&gt;Hello,&nbsp;&lt;\/p&gt;&lt;p&gt;I recently started using LS-Dyna. In AnsysMechanical, I used to define boundary conditions in terms of displacement fields. Apparently, I cannot do the same thing in&nbsp;LS-dyna. It seems that the displacement command is ignored.&nbsp;&lt;\/p&gt;&lt;p&gt;Nevertheless, I can define other boundary conditions in terms of initial velocity and load. But as I want to study the buckling problem in structure, load conditions can lead to non-stable solution.&lt;\/p&gt;&lt;p&gt;I suppose I missed something, does anyone have a solution? Thank you !&lt;\/p&gt;&lt;p&gt;The picture below is from a ball compression test. The lower support is fixed, while the displacement command is defined for the upper one.&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2026\/01\/07-01-2026-1767782332-mceclip0.png\" \/>&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-449899","topic","type-topic","status-publish","hentry","topic-tag-boundary-condition"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_forum_id":["27814"],"_bbp_topic_id":["449899"],"_bbp_author_ip":["185.13.183.159"],"_bbp_last_reply_id":["449946"],"_bbp_last_active_id":["449946"],"_bbp_last_active_time":["2026-01-07 15:00:48"],"_bbp_reply_count":["2"],"_bbp_reply_count_hidden":["0"],"_bbp_voice_count":["3"],"_bbp_engagement":["47278","275204","240"],"_btv_view_count":["196"],"_bbp_topic_status":["unanswered"],"_bbp_subscription":["275204","240"]},"test":"racheltetmet-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/449899","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\/449899\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=449899"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}