{"id":381780,"date":"2024-09-06T20:51:13","date_gmt":"2024-09-06T20:51:13","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/reaction-forces-and-moments-during-random-vibration-at-local-coordinate-systems\/"},"modified":"2024-09-06T20:51:13","modified_gmt":"2024-09-06T20:51:13","slug":"reaction-forces-and-moments-during-random-vibration-at-local-coordinate-systems","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/reaction-forces-and-moments-during-random-vibration-at-local-coordinate-systems\/","title":{"rendered":"Reaction forces and moments during random vibration at local coordinate systems"},"content":{"rendered":"<p>&lt;p&gt;Hi all,&lt;\/p&gt;&lt;p&gt;I am attempting to extract reaction forces and moments at named selections during random vibration analysis. I am mostly following the method outlined here:&lt;\/p&gt;&lt;p&gt;<a href=\"https:\/\/www.padtinc.com\/2011\/06\/15\/retrieving-accurate-psd-reaction-forces-in-ansys-mechanical\/\" target=\"_blank\" rel=\"noopener\">https:\/\/www.padtinc.com\/2011\/06\/15\/retrieving-accurate-psd-reaction-forces-in-ansys-mechanical\/<\/a>&lt;\/p&gt;&lt;p&gt;My problem is that the forces and moments are delivered in the global coordinate system, and since this is a random analysis, they are always positive. So I cannot use a typical transformation matrix to transfer them into another coordinate system. Is there another method I can use to do this?&lt;\/p&gt;&lt;p&gt;I have also experimented with using NROTAT to rotate the nodes of interest and then using *GET to extract the force at each node, but I can&#8217;t extract moments this way with a model composed of 3D elements.&lt;\/p&gt;&lt;p&gt;Thanks for your assistance.&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-381780","topic","type-topic","status-publish","hentry","topic-tag-ansys-mechanical-apdl","topic-tag-force-reaction","topic-tag-random-vibration"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["452503","490","20905"],"_bbp_author_ip":["163.116.248.51"],"_btv_view_count":["1549"],"_bbp_topic_status":["unanswered"],"_bbp_notification_enabled":["452503"],"_bbp_topic_id":["381780"],"_bbp_forum_id":["27791"],"_bbp_engagement":["490","20905","452503"],"_bbp_voice_count":["3"],"_bbp_reply_count":["6"],"_bbp_last_reply_id":["382358"],"_bbp_last_active_id":["382358"],"_bbp_last_active_time":["2024-09-11 15:57:29"]},"test":"justin-nekota2ngc-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/381780","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\/381780\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=381780"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}