{"id":303415,"date":"2023-08-25T18:16:34","date_gmt":"2023-08-25T18:16:34","guid":{"rendered":"\/forum\/forums\/reply\/303415\/"},"modified":"2023-08-25T18:16:34","modified_gmt":"2023-08-25T18:16:34","slug":"303415","status":"publish","type":"reply","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/reply\/303415\/","title":{"rendered":"Reply To: Validation of non-linear compressive behaviour of resin-printed structures"},"content":{"rendered":"<p>&lt;p&gt;Another (maybe remote) possibility is that <em>physically<\/em> (during testing), multiple side-by-side columns of the porous structure (such as the one represented with your 1\/4 symmetry model) deflect laterally as a group when the structure is compressed (with each individual column deforming in much the same way beam buckling is depicted in engineering textbooks (<a href=\"https:\/\/en.wikipedia.org\/wiki\/Buckling\">Buckling &#8211; Wikipedia<\/a>):&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2023\/08\/25-08-2023-1692985940-mceclip0.png\" \/>&lt;\/p&gt;&lt;p&gt;With symmetry models, we usually constrain the normal component of displacement on the symmetry surfaces. You didn&#8217;t mention doing this yourself, but if you did, that would prevent the model from exhibiting the deformation mode that I&#8217;m describing.&lt;\/p&gt;&lt;p&gt;I am a little confused by the image of your model (which appears to be 1\/4 symmetry of the geometry of a single &#8220;column&#8221;) and your reference to &#8220;1\/14 symmetry&#8221; &#8211; I may be missing something that renders my discussion inapplicable.&lt;\/p&gt;&lt;p&gt;Is the model that Mechanical creates for you meshed with SOLID285?:&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2023\/08\/25-08-2023-1692986934-mceclip1.png\" \/>&lt;\/p&gt;&lt;p&gt;Given your use of an Ogden material model, I suspect this is the case, but if not, these <em>do<\/em> tend to be less susceptible to mesh entanglement problems such as the one you&#8217;re experiencing.&lt;\/p&gt;&lt;p&gt;Best,&lt;\/p&gt;&lt;p&gt;Bill&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-303415","reply","type-reply","status-publish","hentry"],"aioseo_notices":[],"acf":[],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/replies\/303415","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\/303415\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=303415"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}