{"id":285206,"date":"2023-05-23T04:07:24","date_gmt":"2023-05-23T04:07:24","guid":{"rendered":"\/forum\/forums\/topic\/highly-distorted\/"},"modified":"2023-05-23T04:07:24","modified_gmt":"2023-05-23T04:07:24","slug":"highly-distorted","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/highly-distorted\/","title":{"rendered":"Highly distorted"},"content":{"rendered":"<p class=\"MsoNormal\"><span lang=\"EN-US\" style=\"font-family: 'Times New Roman',serif\">Hello, I&#8217;m currently working on breast compression simulation. The simulation is moving the upper board downward to compress the breasts. Here is a&nbsp; some images for reference.<\/span><\/p>\n<p class=\"MsoNormal\"><span lang=\"EN-US\" style=\"font-family: 'Times New Roman',serif\"><img decoding=\"async\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2023\/05\/23-05-2023-1684814306-1.png\" alt=\"\"><\/span><\/p>\n<p class=\"MsoNormal\"><span lang=\"EN-US\" style=\"font-family: 'Times New Roman',serif\">The boundary conditions are set as follows<\/span><\/p>\n<p class=\"MsoNormal\"><span lang=\"EN-US\" style=\"font-family: 'Times New Roman',serif\"><img decoding=\"async\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2023\/05\/23-05-2023-1684814444-2.png\" alt=\"\"><\/span><\/p>\n<p class=\"MsoNormal\"><span lang=\"EN-US\" style=\"font-family: 'Times New Roman', serif;font-size: 14pt\"><span lang=\"EN-US\" style=\"font-family: Calibri, sans-serif\">The geometry of breast as shown in the image below<\/span><\/span><\/p>\n<p class=\"MsoNormal\"><span lang=\"EN-US\" style=\"font-family: 'Times New Roman',serif\"><span lang=\"EN-US\" style=\"font-size: 12.0pt;font-family: 'Calibri',sans-serif\"><img decoding=\"async\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2023\/05\/23-05-2023-1684814527-3.png\" alt=\"\"><\/span><\/span><\/p>\n<p class=\"MsoNormal\"><span lang=\"EN-US\" style=\"font-family: 'Times New Roman', serif;font-size: 14pt\"><span lang=\"EN-US\" style=\"font-family: Calibri, sans-serif\">The material properties are using the Mooney-Rivlin model, and the values are obtained from the paper.<\/span><\/span><\/p>\n<p class=\"MsoNormal\"><span lang=\"EN-US\" style=\"font-family: 'Times New Roman', serif;font-size: 14pt\"><span lang=\"EN-US\" style=\"font-family: Calibri, sans-serif\">The mesh I use linear hexahedron and element size I use 1 mm , it can get 425681 nodes and 598742 element. And the average element quality is 0.77688.<\/span><\/span><\/p>\n<p class=\"MsoNormal\"><span lang=\"EN-US\">The goal is to move the upper board downward by 100mm to compress the breast. The simulation is divided into multiple steps, with each step moving the board downward by only 1mm. However, when upper board downward by 84mm, a high distortion issue occurs, as shown in the image below.<\/span><\/p>\n<p class=\"MsoNormal\"><span lang=\"EN-US\"><img decoding=\"async\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2023\/05\/23-05-2023-1684814616-0.png\" alt=\"\"><\/span><\/p>\n<p class=\"MsoNormal\"><span lang=\"EN-US\" style=\"font-size: 14pt\"><span lang=\"EN-US\" style=\"font-family: Calibri, sans-serif\">After the error occurred, I checked the residual force and found that there were no issues in other areas except for the initial contact surface between the breast and the upper board. Convergence issues were observed, and the mesh dostortion can also be seen, as shown in the image below.<\/span><\/span><\/p>\n<p class=\"MsoNormal\"><span lang=\"EN-US\" style=\"font-size: 14pt\"><span lang=\"EN-US\" style=\"font-family: Calibri, sans-serif\"><img decoding=\"async\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2023\/05\/23-05-2023-1684814720-mceclip0.png\"><\/span><\/span><\/p>\n<p class=\"MsoNormal\"><strong><span lang=\"EN-US\">I have already tried change element type into tetrahedron and add a nonlinear adaptive region, or decreasing the displacement values at each step, but it still cannot achieve convergence. I would like to know if there are any other ways to solve this error?<\/span><\/strong><\/p>\n<p class=\"MsoNormal\"><span lang=\"EN-US\">Thank everyone!<\/span><\/p>\n<p class=\"MsoNormal\">&nbsp;<\/p>\n","protected":false},"template":"","class_list":["post-285206","topic","type-topic","status-closed","hentry","topic-tag-error","topic-tag-mechanical"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["285206","13640"],"_bbp_author_ip":["23.39.172.6"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["881"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["285206"],"_bbp_forum_id":["27791"],"_bbp_engagement":["13640","285206"],"_bbp_voice_count":["2"],"_bbp_reply_count":["7"],"_bbp_last_reply_id":["285430"],"_bbp_last_active_id":["285430"],"_bbp_last_active_time":["2023-05-24 06:55:29"]},"test":"jiaweiii0610gapp-nthu-edu-tw"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/285206","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\/285206\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=285206"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}