{"id":48723,"date":"2020-10-05T21:45:21","date_gmt":"2020-10-05T21:45:21","guid":{"rendered":"\/forum\/forums\/topic\/need-help-understanding-an-error-in-fatigue-module\/"},"modified":"2021-04-28T18:25:36","modified_gmt":"2021-04-28T18:25:36","slug":"need-help-understanding-an-error-in-fatigue-module","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/need-help-understanding-an-error-in-fatigue-module\/","title":{"rendered":"Need help understanding an error in Fatigue Module"},"content":{"rendered":"<p>Hello everyone,n\u00a0nI\u2019m experiencing a problem with Fatigue Module and need help understanding if I\u2019m doing something wrong or if it\u2019s a software bug. Let me explain.nI\u2019m simulating the strain-based fatigue life of a Ti6Al4v part. The material properties were taken from the paper \u201cFatigue behavior of Ti-6Al-4V ELI including mean stress effects (Patricio E. Carrion et al, 2017)\u201d as seen on the picture.n\u00a0\u00a0n<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/XN93M6SIUC60\/carrion.png\" width=\"687\" height=\"492\" \/>nThe problem lies in the value of the Cyclic strain hardening exponent (n\u2019) being 0.017. I performed a series of tests and Ansys does not seem to accept values below 0.03 regardless of other material properties or the case being studied, always resulting in the generic \u201cAn error occurred inside the FATIGUE module.\u201dnI initially thought it was a problem with the value reported in the article, but the \u201cA study of fatigue notch sensibility on titanium alloy TiAl6V4 parts manufactured by selective laser melting (L.P. Borrego, 2018)\u201d finds similar results, as seen on the picture.n\u00a0n<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/BPKD7O0YVU6X\/borrego.png\" width=\"890\" height=\"90\" \/>nIn order to verify if the problem is solvable, I used the calculator found on efatigue.com which gives the same results as Ansys Fatigue Module for the problem with n\u2019>0.03 and can solve the problem for n\u2019<0.03 were fatigue Module can\u2019t. n\u00a0nSo, is this a bug on Ansys or I\u2019m missing something? Can anybody replicate this error for a generic problem and material with n<0.03?n\n<\/p>\n","protected":false},"template":"","class_list":["post-48723","topic","type-topic","status-closed","hentry","topic-tag-fatigue","topic-tag-mechanical"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["20947"],"_bbp_old_topic_author_name_id":["Anonymous"],"_bbp_old_is_topic_anonymous_id":["false"],"_bbp_old_closed_status_id":["closed"],"_bbp_author_ip":["(\u0004\u0001M??L??\u0003\b9?\u0001 ?"],"_bbp_old_sticky_status_id":["normal"],"_bbp_status":["publish"],"_bbp_likes_count":["0","0","0","0","0"],"_btv_view_count":["1284"],"_bbp_subscription":["245857"],"_bbp_topic_status":["unanswered"],"_bbp_topic_id":["48723"],"_bbp_forum_id":["27791"],"_bbp_engagement":["490","171516"],"_bbp_voice_count":["2"],"_bbp_reply_count":["3"],"_bbp_last_reply_id":["129184"],"_bbp_last_active_id":["129184"],"_bbp_last_active_time":["2020-10-07 14:09:53"]},"test":"arthursa"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/48723","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\/48723\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=48723"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}