{"id":169541,"date":"2022-05-18T08:08:55","date_gmt":"2022-05-18T08:08:55","guid":{"rendered":"\/forum\/forums\/topic\/questions-regarding-modal-analysis-and-random-vibration-analysis\/"},"modified":"2022-06-01T00:18:47","modified_gmt":"2022-06-01T00:18:47","slug":"questions-regarding-modal-analysis-and-random-vibration-analysis","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/questions-regarding-modal-analysis-and-random-vibration-analysis\/","title":{"rendered":"Questions regarding Modal Analysis and Random Vibration Analysis"},"content":{"rendered":"<div class=\"Item-Body\">\n<div class=\"Message userContent\">\n<p>Hello,<\/p>\n<p>I&#039;m trying to perform my first Modal And Random Vibration Analysis.<\/p>\n<p>I&#039;ve watched some different Ansys tutorials and read the Mechanical User&#039;s Guide, but I&#039;ve still have some questions regarding these topics. <\/p>\n<p><strong>Question 1: Number of modes to use based on maximum freq in PSD excitation table<\/strong><\/p>\n<p>I have a PSD curve that goes from 0-2000Hz. <\/p>\n<p>According to Mechanical User&rsquo;s Guide: &ldquo;A conservative rule of thumb is to include modes that cover 1.5 times the maximum frequency in the PSD excitation table&rdquo;. Hence, I select all modes up to 3000Hz (which is 101 if I limit search to range). <\/p>\n<div class=\"embedExternal embedImage\">\n<div class=\"embedExternal-content\">\n<a class=\"embedImage-link\" href=\"\/forum\/wp-content\/uploads\/forum-uploads\/302\/H4G6RCMNTYFX.png\" rel=\"nofollow noopener\" target=\"_blank\"><br \/>\n<img decoding=\"async\" class=\"embedImage-img\" src=\"\/forum\/wp-content\/uploads\/forum-uploads\/302\/H4G6RCMNTYFX.png\" alt=\"image.png\" \/><br \/>\n<\/a><\/p>\n","protected":false},"template":"","class_list":["post-169541","topic","type-topic","status-closed","hentry","topic-tag-ansys-mechanical","topic-tag-modal-analysis","topic-tag-random-vibration"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_btv_view_count":["4888"],"_bbp_likes_count":["0"],"_edit_lock":["1658926911:76739"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["169541"],"_bbp_forum_id":["27791"],"_bbp_engagement":["14","25148"],"_bbp_voice_count":["2"],"_bbp_reply_count":["4"],"_bbp_last_reply_id":["214938"],"_bbp_last_active_id":["214938"],"_bbp_last_active_time":["2022-06-01 00:18:47"]},"test":"albin-linderstamsaabgroup-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/169541","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\/169541\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=169541"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}