{"id":461629,"date":"2026-07-21T21:53:55","date_gmt":"2026-07-21T21:53:55","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/cqc-spectrum-method-hand-calc\/"},"modified":"2026-07-21T21:53:55","modified_gmt":"2026-07-21T21:53:55","slug":"cqc-spectrum-method-hand-calc","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/cqc-spectrum-method-hand-calc\/","title":{"rendered":"CQC Spectrum Method &#8211; Hand Calc"},"content":{"rendered":"<p class=\"MsoPlainText\">In Mechanical, I&#8217;m running a modal analysis followed by a spectrum analysis.&nbsp; With command snippets, I&#8217;m doing a manual comparison of FSUM data at a location on a model.<span>&nbsp; <\/span>I&#8217;m manually extracting FSUM data from the modal analysis for every mode at a location.<span>&nbsp; <\/span>I then manually extract the modal coefficients from the spectrum analysis using *GET.<span>&nbsp; <\/span>With some basic APDL math scripting, I manually multiply the modal FSUM data of each mode, by its corresponding modal coefficient.<span>&nbsp; <\/span>Then in the last step, I SRSS all of those values to get the actual FSUM data for the location.<span>&nbsp; <\/span>It matches what I get if I just issue FSUM from the spectrum analysis.<span>&nbsp; <\/span>In this scenario, the spectrum analysis uses the SRSS method.<\/p>\n<p class=\"MsoPlainText\">Next, I want to redo the manual verification of the FSUM data using CQC method instead.<span>&nbsp; <\/span>But coding the basic math of CQC is more complicated.<span>&nbsp; <\/span>I would like to know if anyone has coded the CQC math before.<\/p>\n","protected":false},"template":"","class_list":["post-461629","topic","type-topic","status-publish","hentry","topic-tag-mechanical"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_forum_id":["27791"],"_bbp_topic_id":["461629"],"_bbp_subscription":["79744","672007"],"_bbp_author_ip":[null],"_bbp_last_reply_id":["461756"],"_bbp_last_active_id":["461756"],"_bbp_last_active_time":["2026-07-23 15:44:46"],"_bbp_reply_count":["4"],"_bbp_reply_count_hidden":["0"],"_bbp_engagement":["1","672007","79744"],"_bbp_likes_count":["0"],"_btv_view_count":["37"],"application":["Mechanical"],"emailnotification":[null],"_bbp_topic_status":["unanswered"],"_bbp_voice_count":["3"]},"test":"mattprime-engineer-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/461629","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\/461629\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=461629"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}