{"id":305838,"date":"2023-09-10T22:04:59","date_gmt":"2023-09-10T22:04:59","guid":{"rendered":"\/forum\/forums\/topic\/determining-yield-stress-for-nonlinear-stress-strain-relationship\/"},"modified":"2023-09-19T14:56:51","modified_gmt":"2023-09-19T14:56:51","slug":"determining-yield-stress-for-nonlinear-stress-strain-relationship","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/determining-yield-stress-for-nonlinear-stress-strain-relationship\/","title":{"rendered":"Determining yield stress for nonlinear stress-strain relationship"},"content":{"rendered":"

Hello!<\/p>\n

BACKGROUND: I am using some nonlinear temperature-dependent stress-strain data in an ANSYS Transient Structural simulation, entered as a multilinear model in a command object as APDL. The data I am using contains of a series of curves, one for each temperature. I am using the TB, TBTEMP, and TBPT commands to enter in plastic strain versus true stress data for each temperature, and I am using the MPTEMP and MPDATA to enter in the elastic modulus data.<\/p>\n

The issue is that there is not a clear yield point, and I am not sure what the best way to determine this in a systematic way. <\/p>\n

Should I use a 0.2% offset as shown in the following plot? The red line is one of the stress-strain curves I am using, and the blue line represents the 0.2% offset. I am concerned about this because, to me, it looks like plastic deformation is already occurring before this yield point.<\/p>\n

<\/a><\/p>\n

Previously, I was representing the stress-strain curve with a series of line segments (something like what is shown below, in green). This follows the stress-strain curve more nicely but it also means that yielding starts at a much lower stress. Is this a better method? <\/p>\n

<\/a><\/p>\n

Thank you!<\/p>\n

 <\/p>\n","protected":false},"template":"","class_list":["post-305838","topic","type-topic","status-closed","hentry","topic-tag-ansys-apdl","topic-tag-Multilinearisotropichardeningmodel-1","topic-tag-stress-strain-curve","topic-tag-transient-structural","topic-tag-yield-point-1"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["168004","240","170445"],"_bbp_author_ip":["23.52.43.81"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["1434"],"_edit_lock":["1694383686:52623"],"_bbp_status":["publish"],"_bbp_topic_status":["unanswered"],"_bbp_topic_id":["305838"],"_bbp_forum_id":["27791"],"_bbp_engagement":["240","168004","170445"],"_bbp_voice_count":["3"],"_bbp_reply_count":["3"],"_bbp_last_reply_id":["307463"],"_bbp_last_active_id":["307463"],"_bbp_last_active_time":["2023-09-19 14:56:44"]},"test":"rgdiscovery"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/305838","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\/305838\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=305838"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}