{"id":300902,"date":"2023-08-10T15:29:33","date_gmt":"2023-08-10T15:29:33","guid":{"rendered":"\/forum\/forums\/reply\/300902\/"},"modified":"2023-08-11T08:41:16","modified_gmt":"2023-08-11T08:41:16","slug":"300902","status":"publish","type":"reply","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/reply\/300902\/","title":{"rendered":"Reply To: Enhanced assumed strain method SOLID185, KEYOPT(2)=2,KEYOPT(6)=0"},"content":{"rendered":"<p>&lt;p&gt;&nbsp;&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;&lt;p&gt;Hello,&lt;\/p&gt;&lt;p&gt;I have tried with the following enhanced interpolation matrix (9+3):&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2023\/08\/10-08-2023-1691680167-mceclip1.png\" \/>&lt;\/p&gt;&lt;p&gt;This gives indentical results with SOLID185, (KEYO(2)=2 and KEYO(6)=0) when the hexahedral is perfect cube and traditional 2x2x2 Gaussian quadrature rule is used and same 6&times;6 transformation matrix T_0 is used than in <em>Andelfinger and Ramm([321]<\/em>&nbsp; paper.&lt;\/p&gt;&lt;p&gt;However when the hexahedral element is initially parallelepiped or arbitrarily distorted there is difference between the results so this enhanced interpolation matrix M_xi is not correct one.&lt;\/p&gt;&lt;p&gt;I also tried this 9+4 version of the enhanced interpolation matrix, but it gives almost identical results with the above one:&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2023\/08\/10-08-2023-1691680885-mceclip2.png\" \/>&lt;\/p&gt;&lt;p&gt;I have read many PhD theses and scientific publications about these EAS methods, but I haven&rsquo;t yet found the 9+4 version for the enhanced interpolation matrix which is mentioned in the Ansys Theory manual.&lt;\/p&gt;&lt;p&gt;Could someone explain or show what is the correct form for the matrix and are there other aspects to consider ? This isn&rsquo;t explained in the Ansys Theory Manual clearly.&lt;\/p&gt;&lt;p&gt;Best regards,&lt;\/p&gt;&lt;p&gt;Pirkka&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-300902","reply","type-reply","status-publish","hentry"],"aioseo_notices":[],"acf":[],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/replies\/300902","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/replies"}],"about":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/types\/reply"}],"version-history":[{"count":0,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/replies\/300902\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=300902"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}