{"id":442625,"date":"2025-09-30T05:35:33","date_gmt":"2025-09-30T05:35:33","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/base-excitation-is-not-working-correctly-in-the-time-history-response-analysis\/"},"modified":"2025-09-30T05:35:33","modified_gmt":"2025-09-30T05:35:33","slug":"base-excitation-is-not-working-correctly-in-the-time-history-response-analysis","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/base-excitation-is-not-working-correctly-in-the-time-history-response-analysis\/","title":{"rendered":"Base excitation is not working correctly in the time-history response analysis."},"content":{"rendered":"<p>&lt;p&gt;Message This analysis was performed using modal analysis with the mode superposition method, and the acceleration is applied in the vertical (up&ndash;down) direction. The model should be fixed, but the entire structure moves (see the photos below). As a result, the expected response waveform is not obtained. What can be done to fix this? I would appreciate any advice.&lt;\/p&gt;&lt;p&gt;Analysis Settings\uff08Input\uff09&lt;\/p&gt;&lt;p&gt;<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2025\/09\/30-09-2025-1759209653-test.png\" alt=\"\" width=\"943\" height=\"240\" \/>&lt;\/p&gt;&lt;p&gt;fixed surface&lt;\/p&gt;&lt;p&gt;<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2025\/09\/30-09-2025-1759209704-testt.png\" alt=\"\" width=\"942\" height=\"607\" \/>&lt;\/p&gt;&lt;p&gt;Result\uff08Output\uff09&lt;\/p&gt;&lt;p&gt;<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2025\/09\/30-09-2025-1759210170-testtt.png\" alt=\"\" width=\"945\" height=\"209\" \/>&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-442625","topic","type-topic","status-publish","hentry","topic-tag-dynamic-analysis-2","topic-tag-mode-superposition","topic-tag-oscillating","topic-tag-oscillation","topic-tag-Transientvibration-1"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_forum_id":["27791"],"_bbp_topic_id":["442625"],"_bbp_subscription":["565445","240"],"_bbp_author_ip":["183.91.104.75"],"_bbp_last_reply_id":["442672"],"_bbp_last_active_id":["442672"],"_bbp_last_active_time":["2025-09-30 11:33:32"],"_bbp_reply_count":["2"],"_bbp_reply_count_hidden":["0"],"_bbp_voice_count":["2"],"_bbp_engagement":["565445","240"],"_btv_view_count":["286"],"_bbp_topic_status":["unanswered"]},"test":"22ek075ms-dendai-ac-jp"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/442625","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\/442625\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=442625"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}