{"id":33224,"date":"2019-02-11T21:25:25","date_gmt":"2019-02-11T21:25:25","guid":{"rendered":"\/forum\/forums\/topic\/harmonic-response-analysis-found-only-radially-symmetric-modes\/"},"modified":"2019-02-11T21:25:25","modified_gmt":"2019-02-11T21:25:25","slug":"harmonic-response-analysis-found-only-radially-symmetric-modes","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/harmonic-response-analysis-found-only-radially-symmetric-modes\/","title":{"rendered":"harmonic response analysis found only radially symmetric modes"},"content":{"rendered":"<p>Hello,<\/p>\n<p><\/p>\n<p>&nbsp;<\/p>\n<p><\/p>\n<p>i have performed a modal analysis of prestressed ideal circular membrane (homogenous), clamped on its edges.<\/p>\n<p>Modal analysis found following normal modes (in Hertz): 55,8; 89,06; 119,46;&nbsp;128,45;&nbsp;148,55;&nbsp;163,46;&nbsp;176,89; 198; and so on<\/p>\n<p>Next i performed a harmonic analysis, because i wanted to know the displacement&nbsp; at different frequencies. <\/p>\n<p>The load was 20Pa pressure on whole area of membrane:&nbsp;<br \/><img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/b52b263f-1db2-4f6c-a2d6-a92e014c7143\/c14aa61e-1812-4bcf-88a2-a9f101607c11_e.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n<p>Suprisingly, amplitude is critical only for RADIALLY SYMMETRIC modes: 55,58Hz; 128,45; 198Hz&nbsp;<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/b52b263f-1db2-4f6c-a2d6-a92e014c7143\/9703509f-e448-4fa1-804a-a9f1015fc3e1_d.jpg?width=690&amp;upscale=false\" alt=\"amplitude at different freq.\"><\/p>\n<p>Why is that ?&nbsp;<\/p>\n<p>Why only radially symmetric normal modes are critical?<\/p>\n<p>By the way (just for explanation), the radially symetric mode from the following picture is 1st mode and 4th mode&nbsp;<img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/b52b263f-1db2-4f6c-a2d6-a92e014c7143\/cc0d4b51-a0fc-4a68-acac-a9f1016209dd_f.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n","protected":false},"template":"","class_list":["post-33224","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["5396"],"_bbp_old_topic_author_name_id":["Anonymous"],"_bbp_old_is_topic_anonymous_id":["false"],"_bbp_old_closed_status_id":["publish"],"_bbp_author_ip":[null],"_bbp_old_sticky_status_id":["normal"],"_bbp_likes_count":["0","0","0","0","0"],"_btv_view_count":["407"],"_bbp_subscription":["236794"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["33224"],"_bbp_forum_id":["27791"],"_bbp_engagement":["158123","160648"],"_bbp_voice_count":["2"],"_bbp_reply_count":["2"],"_bbp_last_reply_id":["77556"],"_bbp_last_active_id":["77556"],"_bbp_last_active_time":["2019-02-11 23:15:02"]},"test":"kravky"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/33224","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\/33224\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=33224"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}