{"id":363318,"date":"2024-04-20T14:57:45","date_gmt":"2024-04-20T14:57:45","guid":{"rendered":"\/forum\/forums\/topic\/underground-storage-tank-boundary-conditions\/"},"modified":"2024-04-20T14:57:45","modified_gmt":"2024-04-20T14:57:45","slug":"underground-storage-tank-boundary-conditions","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/underground-storage-tank-boundary-conditions\/","title":{"rendered":"Underground storage tank boundary conditions"},"content":{"rendered":"<p>Hi,<\/p>\n<p>I want to make a static strutural analysis on a buried HDPE water tank for my thesis.<\/p>\n<p>For material I used the built in Plastic, HDPE one from the engineering data<\/p>\n<p>I made the model, it is a midsurface and halfed, as seen below.<br \/>The top cylindrical face is flush with the surface.<\/p>\n<p><img decoding=\"async\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2024\/04\/20-04-2024-1713623095-5.PNG\" alt=\"\"><\/p>\n<p>Mesh looks good. Mainly Quad4, element quality avarage is 0,928 and there are 59000 elements<\/p>\n<p><img decoding=\"async\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2024\/04\/20-04-2024-1713622833-3.PNG\" alt=\"\"><\/p>\n<p>I applied the following boundary conditions:<\/p>\n<p>A: Displacement 0mm in X,Y,Z<br \/>B: Displacement 0mm in X<br \/>C: Displacement 0mm in Y<br \/>D: Variable pressure normal to surface &#8211; this is for the soil pressure, see picture. Would be better apply only in the Y direction, but can&#8217;t figure it out how to do that.<br \/>E: Pressure for the soil from below &#8211; An elastic support should be better? Please help with this.<\/p>\n<p>I would be happy if i can loose the feets from the tank bottom with other boundary conditions.<\/p>\n<p><img decoding=\"async\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2024\/04\/20-04-2024-1713622970-4.PNG\" alt=\"\"><img decoding=\"async\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2024\/04\/20-04-2024-1713623245-6.PNG\" alt=\"\"><\/p>\n<p>Analysis settings:<\/p>\n<ul>\n<li>Large Deflection ON<\/li>\n<li>Quasy-Static Solution ON<\/li>\n<li>Initial substeps 500<\/li>\n<li>Minimum substeps 200<\/li>\n<li>Maximum substeps 10000<\/li>\n<\/ul>\n<p><img decoding=\"async\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2024\/04\/20-04-2024-1713624580-8.PNG\" alt=\"\"><\/p>\n<p><img decoding=\"async\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2024\/04\/20-04-2024-1713624387-8.PNG\" alt=\"\"><\/p>\n<p>I always got &#8220;The solver engine was unable to converge on a solution for the nonlinear problem as contrained.&#8221;<\/p>\n<p>How can I solve this problem?<br \/>Thanks in advance<\/p>\n","protected":false},"template":"","class_list":["post-363318","topic","type-topic","status-closed","hentry","topic-tag-mechanical","topic-tag-static-structural","topic-tag-structural-nonlinear","topic-tag-unconverged-solution","topic-tag-workbench"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["344008","240"],"_bbp_author_ip":["23.206.193.41"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["348"],"_bbp_topic_status":["unanswered"],"_bbp_topic_id":["363318"],"_bbp_forum_id":["27791"],"_bbp_engagement":["240","344008"],"_bbp_voice_count":["2"],"_bbp_reply_count":["1"],"_bbp_last_reply_id":["363348"],"_bbp_last_active_id":["363348"],"_bbp_last_active_time":["2024-04-21 11:52:18"]},"test":"torokzolimailbox-unideb-hu"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/363318","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\/363318\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=363318"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}