{"id":163846,"date":"2021-11-09T20:10:21","date_gmt":"2021-11-09T20:10:21","guid":{"rendered":"\/forum\/forums\/topic\/transient-vs-static-loading\/"},"modified":"2021-11-24T14:44:05","modified_gmt":"2021-11-24T14:44:05","slug":"transient-vs-static-loading","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/transient-vs-static-loading\/","title":{"rendered":"Transient Vs Static Loading"},"content":{"rendered":"<div class=\"Item-Body\">\n<div class=\"Message userContent\">\n<p>Pardon me, this question has been asked before, but the answers are not clear. <\/p>\n<p>Going by some text and convention, sudden loads in a transient analysis should result in higher stress levels than a static analysis. However, in my case, the results for a static analysis are higher. Could it simply indicate higher\/erroneous damping? <\/p>\n<p>My approach (for a 4 ms over-pressurization event) is as follows: <\/p>\n<ol>\n<li>Modal analysis (mode participation factor) to get the lowest frequency\/mode shape, since it is most likely to cause vibration. <\/li>\n<li>Run a static analysis with appropriate boundary conditions (Large deflections on, material nonlinearity)<\/li>\n<li>Use Rayleigh damping and calculate mass\/stiffness coefficients based on a frequency range that captures the first two fundamental freq. with 1.5% damping <\/li>\n<li>Run a transient analysis with appropriate boundary conditions (Large deflections on, material nonlinearity) with max time step that is 1\/20th the time period of the lowest freq. <\/li>\n<\/ol>\n<p>Thank you <\/p>\n<p><\/p>\n<\/p>\n<p><a class=\"atMention\" data-username=\"peteroznewman\" data-userid=\"636\" href=\"https:\/\/forum.webdevonline.net\/profile\/peteroznewman\">@peteroznewman<\/a> ,<a class=\"atMention\" data-username=\"SandeepMedikonda\" data-userid=\"3272\" href=\"https:\/\/forum.webdevonline.net\/profile\/SandeepMedikonda\">@SandeepMedikonda<\/a> , do you have some tips? <\/p>\n<p>Here&#039;s my modal data that drives the transient analysis: <\/p>\n<div class=\"embedExternal embedImage\">\n<div class=\"embedExternal-content\">\n<a class=\"embedImage-link\" href=\"\/forum\/wp-content\/uploads\/forum-uploads\/283\/2HB4PS7L7FHI.png\" rel=\"nofollow noopener\" target=\"_blank\"><br \/>\n<img decoding=\"async\" class=\"embedImage-img\" src=\"\/forum\/wp-content\/uploads\/forum-uploads\/283\/2HB4PS7L7FHI.png\" alt=\"image.png\" \/><br \/>\n<\/a><\/p>\n","protected":false},"template":"","class_list":["post-163846","topic","type-topic","status-closed","hentry","topic-tag-ansys-structural","topic-tag-ansys-student","topic-tag-transient-structural"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_author_ip":[""],"_bbp_old_reply_author_name_id":["Anonymous"],"_bbp_old_is_reply_anonymous_id":["false"],"_btv_view_count":["2036"],"_bbp_likes_count":["0"],"_bbp_subscription":["58521"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["163846"],"_bbp_forum_id":["27791"],"_bbp_engagement":["6","181347"],"_bbp_voice_count":["2"],"_bbp_reply_count":["5"],"_bbp_last_reply_id":["197256"],"_bbp_last_active_id":["197256"],"_bbp_last_active_time":["2021-11-24 14:44:05"]},"test":"doodlerd"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/163846","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\/163846\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=163846"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}