{"id":170603,"date":"2023-06-05T07:04:49","date_gmt":"2023-06-05T07:04:49","guid":{"rendered":"\/knowledge\/forums\/topic\/the-warning-message-is-the-maximum-contact-stiffness-is-too-big-this-may-affect-the-accuracy-of-the-results-why-does-large-contact-stiffness-affect-results-accuracy-3\/"},"modified":"2023-07-31T12:33:25","modified_gmt":"2023-07-31T12:33:25","slug":"the-warning-message-is-the-maximum-contact-stiffness-is-too-big-this-may-affect-the-accuracy-of-the-results-why-does-large-contact-stiffness-affect-results-accuracy-3","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/the-warning-message-is-the-maximum-contact-stiffness-is-too-big-this-may-affect-the-accuracy-of-the-results-why-does-large-contact-stiffness-affect-results-accuracy-3\/","title":{"rendered":"The warning message is: &#8220;The maximum contact stiffness is too big. This may affect the accuracy of the results.&#8221; Why does large contact stiffness affect results accuracy?"},"content":{"rendered":"<p>If the contact stiffness is too large, it can cause a very ill-conditioned matrix. Severely ill-conditioned matrices can lead to numerical roundoff error. (we have a finite span we can cover in double precision, and if the contact stiffness coefficients are too large than the other element&#8217;s stiffness coefficients, then error can accumulate from finite precision math when we try to invert [K] in the sparse direct solver or solve with an iterative solver to a certain level of tolerance).<\/p>\n","protected":false},"template":"","class_list":["post-170603","topic","type-topic","status-publish","hentry","topic-tag-18-1","topic-tag-general","topic-tag-mechanical-apdl","topic-tag-structural-mechanics"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_wp_page_template":["default"],"_bbp_last_active_time":["2\/6\/2023 20:20"],"_bbp_forum_id":["27789"],"_bbp_author_ip":["209.182.204.162"],"_btv_view_count":["2181"],"siebel_km_number":["2050392"],"product_version":["18.1"],"km_published_date":["2017-06-08T17:37:00.000Z"],"family":["Structural Mechanics"],"application_name":["Mechanical APDL"],"_edit_lock":["1704959133:2"]},"test":"articlesansys-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/topics\/170603","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/topics"}],"about":[{"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/types\/topic"}],"version-history":[{"count":0,"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/topics\/170603\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/media?parent=170603"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}