{"id":311345,"date":"2023-10-13T02:17:24","date_gmt":"2023-10-13T02:17:24","guid":{"rendered":"\/forum\/forums\/topic\/impose-a-prescirbed-rotation-around-an-arbitrary-axis\/"},"modified":"2023-10-13T09:32:38","modified_gmt":"2023-10-13T09:32:38","slug":"impose-a-prescirbed-rotation-around-an-arbitrary-axis","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/impose-a-prescirbed-rotation-around-an-arbitrary-axis\/","title":{"rendered":"Impose a prescribed rotation around an arbitrary axis"},"content":{"rendered":"<p>Hi,<\/p>\n<p>I am trying to impose a rotation of the deformable part&nbsp;around an arbitrary axis for prepositioning before an impact.<\/p>\n<p class=\"MsoNormal\">I know that this can be done using *BOUNDARY_PRESCRIBED_MOTION_RIGID_ID if I switch the part to rigid and then manually force its CG to be at the desired centre of rotation by using *PART_INERTIA. However, I need the part to stay deformable for the simulating an impact after the initial prepositioning.<\/p>\n<p class=\"MsoNormal\">My potential workaround is to create a *CONSTRAINED_NODAL_RIGID_BODY_INERTIA using the nodes of the deformable part that I want to rotate so that I can leave the original underlying part deformable and impose the an arbitrary CG location of the overlaid CNRB. Based on the LS-DYNA manual, a rotation imposed to this CNRB through *BOUNDARY_PRESCRIBED_MOTION_RIGID_ID will occur around the CG defined through the manual inertia assignment to the CNRB.<\/p>\n<p class=\"MsoNormal\">&nbsp;<\/p>\n<p class=\"MsoNormal\">However, the rotation imposed to this CNRB still occurs around the original CG&nbsp;of the CNRB and not the node used to manually impose its new inertia properties.<\/p>\n<p class=\"MsoNormal\">Is this due because LS-DYNA gives priority to the inertial properties of the underlying deformable parts? Or is it a bug in the code?<\/p>\n<p class=\"MsoNormal\">Any suggestion to make it work would be helpful.<\/p>\n","protected":false},"template":"","class_list":["post-311345","topic","type-topic","status-closed","hentry","topic-tag-boundary-conditions","topic-tag-ls-dyna"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["295566","3136"],"_bbp_author_ip":["23.206.193.154"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["1236"],"_edit_lock":["1697165341:234806"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["311345"],"_bbp_forum_id":["27814"],"_bbp_engagement":["3136","295566"],"_bbp_voice_count":["2"],"_bbp_reply_count":["10"],"_bbp_last_reply_id":["313118"],"_bbp_last_active_id":["313118"],"_bbp_last_active_time":["2023-10-24 17:32:52"]},"test":"mario-mongiardiniadelaide-edu-au"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/311345","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\/311345\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=311345"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}