{"id":45986,"date":"2020-07-10T13:52:39","date_gmt":"2020-07-10T13:52:39","guid":{"rendered":"\/forum\/forums\/topic\/large-plastic-strain-during-collapse-in-3-point-bending-simulation\/"},"modified":"2020-07-10T13:52:39","modified_gmt":"2020-07-10T13:52:39","slug":"large-plastic-strain-during-collapse-in-3-point-bending-simulation","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/large-plastic-strain-during-collapse-in-3-point-bending-simulation\/","title":{"rendered":"Large plastic strain during collapse in 3 point bending simulation"},"content":{"rendered":"

Hello everyone,<\/p>\n

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I am having some troubles analyzing the collapse of a hollow square tube in a 3 point bending test simulation. Even though I obtain a F-u curve quite close to the expected curve (theoretical and experimental). I have found some points that suffer from excesive plastic strain. Some of them have 1.1 and even -1.1 plastic strain in all directions. Those points are the ones in contact with the rigid force applicator. Also, the point where the collapse occurs, also suffers this large plastic deformations. <\/p>\n

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I used solid185 elements for the tube, with little fillets (if i dont use fillets, the problem is more severe) and conta174 elements for contacts and targe169 elements to model the supports and force applicator (as cylinders). <\/p>\n

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I tried the ERESX,NO option to avoid stress above the limit, I have also tried changing to enhanced strain formulation and simplified enhanced strain formulation (however this two last options have problems converging). <\/p>\n

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How can i decrease this extremely high plastic deformations? I tried several mesh sizes but have the same issues at the end. Below there are some screenshots of the problem at hand.<\/p>\n

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Here is the general scheme of the test<\/p>\n

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\"General<\/p>\n

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A detail of the mesh used<\/p>\n

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\"detailed<\/p>\n

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A cross section of the mesh<\/p>\n

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\"cross<\/p>\n

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Plastic deformation in the x-direction. Notice the point with high plastic deformation<\/p>\n

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\"x<\/p>\n

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von Mises plastic deformation… excesive in one point in the middle<\/p>\n

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\"vm<\/p>\n

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Thanks in advance for your help!<\/p>\n","protected":false},"template":"","class_list":["post-45986","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["18168"],"_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"],"_btv_view_count":["294"],"_bbp_subscription":["253554"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["45986"],"_bbp_forum_id":["27791"],"_bbp_engagement":["179445"],"_bbp_voice_count":["1"],"_bbp_reply_count":["0"],"_bbp_last_reply_id":["0"],"_bbp_last_active_id":["45986"],"_bbp_last_active_time":["2020-07-10 13:52:39"]},"test":"daniellavayen"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/45986","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\/45986\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=45986"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}