{"id":166011,"date":"2022-02-01T15:52:56","date_gmt":"2022-02-01T15:52:56","guid":{"rendered":"\/forum\/forums\/topic\/distribute-a-preassure-in-load-steps-vs-doing-it-in-substeps-in-static-analysis\/"},"modified":"2022-02-04T09:37:09","modified_gmt":"2022-02-04T09:37:09","slug":"distribute-a-preassure-in-load-steps-vs-doing-it-in-substeps-in-static-analysis","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/distribute-a-preassure-in-load-steps-vs-doing-it-in-substeps-in-static-analysis\/","title":{"rendered":"Distribute a preassure in Load Steps vs. doing it in Substeps in Static Analysis"},"content":{"rendered":"<div class=\"Item-Body\">\n<div class=\"Message userContent\">\n<p>Hi everyone,<\/p>\n<p><\/p>\n<\/p>\n<p>I am performing an Static Analysis that consists on putting a pressure of 10 Pa on a model with hyperelastic materials and contact.<\/p>\n<p>After strugging with convergence problems, I found out that there is an unstable position in my simulation because each time I run it crashes at the same point (5Pa). To give you an idea, the model of my simulation goes from one stable position to another stable position.<\/p>\n<p>I took control of contact (pinball, formulation) and set Unsymmetric Newton-Raphson method and it was better but I still had convergence problems. <\/p>\n<p>Then, I tried decreasing time step&#8230; and it didn&#039;t help. However, what worked was putting 5Pa on a Load Step and 5Pa more in the next Load Step. And I don&#039;t understand why.<\/p>\n<p>I took care of having equivalent Time Stepping for both analysis. For example, in the 10Pa per LoadStep case I set initial step number to 10 and in the 5Pa+5Pa case I set initial step number to 5 in each Load Step: in both analysis the initial preassure was 1Pa. I did the same with the max and the min step number. <\/p>\n<p>This makes me think that is not the same applying a pressure in one Load Step than applying half and half in two Load Steps in an Static Analysis and I don&#039;t understand why. Is there any logical reason for this behaviour? Does Ansys do sth different when going from one Load Step to another that doesn&#039;t do when passing from one substep from another?<\/p>\n<p><\/p>\n<\/p>\n<p>Thank you very much,<\/p>\n<p>In&eacute;s<\/p>\n","protected":false},"template":"","class_list":["post-166011","topic","type-topic","status-closed","hentry","topic-tag-convergence","topic-tag-load-step","topic-tag-loadstep-1","topic-tag-static-structural","topic-tag-timestep"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_btv_view_count":["995"],"_bbp_likes_count":["0"],"_bbp_subscription":["241197"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["166011"],"_bbp_forum_id":["27791"],"_bbp_engagement":["240","180472","241197"],"_bbp_voice_count":["3"],"_bbp_reply_count":["7"],"_bbp_last_reply_id":["204250"],"_bbp_last_active_id":["204250"],"_bbp_last_active_time":["2022-02-04 09:37:09"]},"test":"ines-nsoleralumnos-upm-es"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/166011","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\/166011\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=166011"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}