{"id":298987,"date":"2023-08-09T13:31:36","date_gmt":"2023-08-09T13:31:36","guid":{"rendered":"\/forum\/forums\/topic\/participation-factor-and-ratio-of-effective-mass-to-total-mass\/"},"modified":"2023-08-16T11:19:19","modified_gmt":"2023-08-16T11:19:19","slug":"participation-factor-and-ratio-of-effective-mass-to-total-mass","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/participation-factor-and-ratio-of-effective-mass-to-total-mass\/","title":{"rendered":"Participation factor and Ratio of Effective mass to total mass"},"content":{"rendered":"

While doing Modal analysis of one assemby I came across some doubt related to Participation Factor (PF) and Ratio of Effective mass (REM now onwards).. <\/p>\n

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  1. In my modal results in one direction the REM is coming low even after extracting 60 modes , so i just want to know if any structure REM is coming low does it indicates that there is some issue or mistake in our FEM model or just to consider that these structure have very high frequency may be?<\/li>\n
  2. as number of modes extracting limit is up to we will get a ratio near to 90% but right now after 60 modes i am getting only a 20 %. I am suppose to do Random vibration on this which has frequemcy range 20 to 2000 and my 60 modes are going very high almost 8000 HZ.<\/li>\n
  3. as PF is can be used to indicate significant mode , but to decide this what value we should consider as threshold value that above or equal to that i will consider a significant mode, bcz mostly the PF values for me are in the range of 10^-2 to 10^-5. As per knowledge the mode which having PF value 0.1 can be consider as significant mode, but in my case no values are close to this?<\/li>\n<\/ol>\n

    does all these issues indicates that the my fem model is wrong? I am missing anything ?<\/p>\n","protected":false},"template":"","class_list":["post-298987","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["284329","20905"],"_bbp_author_ip":["23.206.193.150"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["3552"],"_edit_lock":["1692184623:217291"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["298987"],"_bbp_forum_id":["27791"],"_bbp_engagement":["20905","284329"],"_bbp_voice_count":["2"],"_bbp_reply_count":["10"],"_bbp_last_reply_id":["301727"],"_bbp_last_active_id":["301727"],"_bbp_last_active_time":["2023-08-16 15:19:39"]},"test":"balaji-bpcoreel-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/298987","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\/298987\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=298987"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}