{"id":342501,"date":"2023-12-31T13:11:56","date_gmt":"2023-12-31T13:11:56","guid":{"rendered":"\/forum\/forums\/topic\/creep-anaysis-on-a-plastic-component-analytical-and-ansys-results-dont-match\/"},"modified":"2023-12-31T13:11:56","modified_gmt":"2023-12-31T13:11:56","slug":"creep-anaysis-on-a-plastic-component-analytical-and-ansys-results-dont-match","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/creep-anaysis-on-a-plastic-component-analytical-and-ansys-results-dont-match\/","title":{"rendered":"Creep anaysis on a plastic component – Analytical and ANSYS results don’t match"},"content":{"rendered":"

Hello everyone,<\/span><\/p>\n

 <\/span><\/p>\n

I’m doing a “Static Structural” analysis on a plastic cover, in order to study the creep behavior. Given the double symmetry of the plate, I study only 1\/4.<\/span><\/p>\n

 <\/span><\/p>\n

I have all the experimental info of the material under examination (sigma-epsilon curves and creep curves) and I tried to set up the analysis on ANSYS Workbench. I implemented an elasto-plastic material, with the appropriate module and with the parameters of the creep model (Time Hardening Power Law, using the ANSYS fitting tool).<\/span><\/p>\n

 <\/span><\/p>\n

I then set up two steps: in the first, very short, I apply the constraints + loads (a known pressure on one side of the component) without considering the creep. In the second step, I activate the creep and have constant pressure (I study for example 4 hours).<\/span><\/p>\n

 <\/span><\/span><\/p>\n

The constants of the Time Hardening Power Law model are C1 = 6.27 E-06, C2 = 1.11, C3 = -0.97186, and C4 = 0. The constants were calculated taking into account MPa and hours.<\/span><\/p>\n

 <\/span><\/p>\n

The total deformation of the plate after 5 hours is 10 mm. After the first step, it deforms by 0.6 mm.<\/span><\/p>\n

 <\/span><\/p>\n

Simulating 4 hours of creep (step 1 = 1 hour and step 2 = 4 hours), I get a maximum equivalent creep strain of 0.037, while from the analytical formula of the Time Hardening Power Law model (using t = 4 hours and the constants), I get 0.005.<\/span><\/p>\n

 <\/span><\/p>\n

What could be causing this discrepancy?<\/span><\/p>\n

 <\/span><\/p>\n

Thanks in advance.<\/span><\/p>\n

 <\/p>\n

\"\"<\/span><\/p>\n","protected":false},"template":"","class_list":["post-342501","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["302591","240"],"_bbp_author_ip":["23.206.193.59"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["3107"],"_bbp_topic_status":["unanswered"],"_edit_lock":["1704028874:244587"],"_bbp_status":["publish"],"_bbp_topic_id":["342501"],"_bbp_forum_id":["27791"],"_bbp_engagement":["240","302591"],"_bbp_voice_count":["2"],"_bbp_reply_count":["18"],"_bbp_last_reply_id":["343037"],"_bbp_last_active_id":["343037"],"_bbp_last_active_time":["2024-01-03 20:52:35"]},"test":"jacopo-bardianipolimi-it"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/342501","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\/342501\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=342501"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}