{"id":458097,"date":"2026-05-13T15:42:56","date_gmt":"2026-05-13T15:42:56","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/particle-and-wall-overlap-issue-in-rocky\/"},"modified":"2026-05-13T15:42:56","modified_gmt":"2026-05-13T15:42:56","slug":"particle-and-wall-overlap-issue-in-rocky","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/particle-and-wall-overlap-issue-in-rocky\/","title":{"rendered":"Particle and Wall Overlap Issue in Rocky"},"content":{"rendered":"<p>&lt;p&gt;Hi,&lt;\/p&gt;&lt;p&gt;I have set up a simple polyhedral particle crushing experiment using Rocky DEM. The particle is released between two plates and made to fall to the bottom plate. After this, a motion frame is designed to make the top wall move gradually toward the bottom wall; initially with a velocity and then when in contact, with a force. However, the walls just pass through each other without doing anything. The top wall meets the bottom wall as if it were a fluid. How can I fix this? I have attached an image to show my setup. Please let me know how I can proceed.&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;&lt;p&gt;The wall has high strength (E = 100 GPa) and the particles (0.8 m diameter) are 5-20 GPa. How can I make this crushing experiment work? Is there something I am doing wrong? Is there a tutorial I could look at to design this experiment in Rocky?&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2026\/05\/13-05-2026-1778686868-mceclip1.png\" \/>&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-458097","topic","type-topic","status-publish","hentry","topic-tag-rocky-dem-1"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_forum_id":["27792"],"_bbp_topic_id":["458097"],"_bbp_subscription":["50057","642030"],"_bbp_author_ip":["139.78.244.32"],"_bbp_last_reply_id":["458466"],"_bbp_last_active_id":["458466"],"_bbp_last_active_time":["2026-05-19 15:47:30"],"_bbp_reply_count":["1"],"_bbp_reply_count_hidden":["0"],"_bbp_voice_count":["2"],"_bbp_engagement":["50057","642030"],"_btv_view_count":["94"],"_bbp_topic_status":["unanswered"]},"test":"imomohokstate-edu"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/458097","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\/458097\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=458097"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}