


{"id":318313,"date":"2023-11-18T19:50:17","date_gmt":"2023-11-18T19:50:17","guid":{"rendered":"\/forum\/forums\/topic\/gravity-causing-rigid-body-motion\/"},"modified":"2023-11-23T17:59:57","modified_gmt":"2023-11-23T17:59:57","slug":"gravity-causing-rigid-body-motion","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/gravity-causing-rigid-body-motion\/","title":{"rendered":"Gravity causing rigid body motion?"},"content":{"rendered":"<p>Hi,<\/p>\n<p>I&#8217;m having an issue where the global acceleration from ACEL seems to be causing rigid body motion in my bridge model.<\/p>\n<p>I have set gravity to -9806.5 mm\/s2 and have my densities and other material properties in matching units (~0.002 &#8211; 0.008 g\/mm3, E in N\/mm2). The model seems to solve correctly when I apply pressure loads on the bridge deck elements but the global gravity load seems to always cause it to fail.<\/p>\n<p>Am I missing something about how ACEL works? I&#8217;ve used DK to apply my boundary conditions. I&#8217;m not sure how the solution can solve with applied loads but not for gravity since surely any issues with my boundary conditions would apply to both cases.&nbsp;<\/p>\n<p>Any advice appreciated thanks.<\/p>\n<p><a class=\"wp-colorbox-image cboxElement\" href=\"\/forum\/wp-content\/uploads\/sites\/2\/2023\/11\/18-11-2023-1700336937-mceclip0.png\"><img decoding=\"async\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2023\/11\/18-11-2023-1700336937-mceclip0.png\"><\/a><\/p>\n","protected":false},"template":"","class_list":["post-318313","topic","type-topic","status-closed","hentry","topic-tag-boundary-conditions","topic-tag-constrain-problem-2","topic-tag-gravity-acceleration-2","topic-tag-static-strucural-1"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["302481","88"],"_bbp_author_ip":["23.52.43.81"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["484"],"_edit_lock":["1700424147:244411"],"_bbp_status":["publish"],"_bbp_topic_status":["unanswered"],"_bbp_topic_id":["318313"],"_bbp_forum_id":["27791"],"_bbp_engagement":["88","302481"],"_bbp_voice_count":["2"],"_bbp_reply_count":["1"],"_bbp_last_reply_id":["318828"],"_bbp_last_active_id":["318828"],"_bbp_last_active_time":["2023-11-21 13:50:12"]},"test":"daniel-woods-6student-manchester-ac-uk"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/318313","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\/318313\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=318313"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}