{"id":389896,"date":"2024-10-16T03:50:46","date_gmt":"2024-10-16T03:50:46","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/fea-fatigue-analysis-with-sinusoidal-non-zero-mean-force-inputs\/"},"modified":"2024-10-16T03:50:46","modified_gmt":"2024-10-16T03:50:46","slug":"fea-fatigue-analysis-with-sinusoidal-non-zero-mean-force-inputs","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/fea-fatigue-analysis-with-sinusoidal-non-zero-mean-force-inputs\/","title":{"rendered":"FEA Fatigue Analysis with sinusoidal non-zero mean force inputs"},"content":{"rendered":"<p>&lt;p&gt;Hi there,&lt;br&gt;&lt;br&gt;I&#8217;m currently using ANSYS2023R2 to complete FEA analysis on a reclaimer structure. More specifically, I&#8217;m investigating the fatigue life of the structure based on different loading scenarios. A disclaimer: the model is very large (100 m long, 60 m high) &#8211; and I have a beefy enough computer system to handle it.&lt;br&gt;&lt;br&gt;Within my static structural, I am inputting three forces in the x,y,z directions respectively. Each force is input as a sin wave, all of which have a non-zero mean and have different phases, amplitudes and frequencies.&lt;br&gt;&lt;br&gt;I have put a fatigue tool into the simulation, and have adjusted the ratio to (min stress \/ max stress) to account for the non-zero mean. I am using the Goodman correction theory.&lt;br&gt;&lt;br&gt;My question is about my fatigue life results. Despite a few stress concentrations that are just due to meshing, my fatigue lives range from 1e5 to 1e6 seconds. This seems fine, but the structure I am simulating has been operating under the same force conditions for over 2 years without structural failure &#8211; which does not reflect the 1e6 seconds FEA predicts.&lt;br&gt;&lt;br&gt;Could this small predicted fatigue life be due to one of my input parameters?&lt;br&gt;&lt;br&gt;Thanks in advance,&lt;br&gt;Ben<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/10\/16-10-2024-1729050475-photo2.png\" alt=\"\" \/><img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/10\/16-10-2024-1729050514-Photo1.png\" alt=\"\" \/>&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-389896","topic","type-topic","status-publish","hentry","topic-tag-mechanicalworkbench-1","topic-tag-fatigue-analysis"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["470682","37673"],"_bbp_author_ip":["134.148.98.235"],"_btv_view_count":["342"],"_bbp_topic_status":["unanswered"],"_bbp_topic_id":["389896"],"_bbp_forum_id":["27791"],"_bbp_engagement":["37673","470682"],"_bbp_voice_count":["2"],"_bbp_reply_count":["3"],"_bbp_last_reply_id":["390261"],"_bbp_last_active_id":["390261"],"_bbp_last_active_time":["2024-10-17 14:52:08"]},"test":"ben-mcpherson12gmail-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/389896","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\/389896\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=389896"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}