{"id":211479,"date":"2022-04-12T09:15:32","date_gmt":"2022-04-12T09:15:32","guid":{"rendered":"\/forum\/forums\/reply\/211479\/"},"modified":"2022-04-12T09:15:32","modified_gmt":"2022-04-12T09:15:32","slug":"211479","status":"publish","type":"reply","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/reply\/211479\/","title":{"rendered":"Reply To: Meshing advice &#8211; tetrahedron to hex"},"content":{"rendered":"<p>Hey<br \/>\nLinear tetrahedral\/triangular elements suffer from three issues:<br \/>\n\u00d4\u00c7\u00c9They have one integration point and are constant strain elements \u00d4\u00c7\u00f4 so we need an extremely fine mesh to capture the strain gradient accurately.<br \/>\n\u00d4\u00c7\u00c9        It&#8217;s difficult to distort the element without changing its volume so they\u00d4\u00c7\u00d6re prone to volumetric locking for nearly or fully incompressible materials and maybe overly stiff.<br \/>\n\u00d4\u00c7\u00c9In the case of bending-dominated problems, linear elements are also prone to shear locking which introduces spurious shear stresses in the part and make it overly stiff regardless of how fine the mesh is created.<br \/>\nLinear hexahedral elements, or the 8-noded hex elements, do not suffer from the first two issues, so they seem like a good alternative to linear tetrahedral elements, hence the general recommendation!<br \/>\nWhile it is a valid suggestion, it&#8217;s not always possible to generate a hexahedral mesh. The above limitations are resolved by introducing mid-side nodes which creates a 10-noded tet element that uses second-order polynomial for shape functions. If the geometry is a combination of sweepable and irregular shapes in such then the combination of brick, tetrahedral, pyramid, or wedge elements is used. Pyramid elements are used in the transition regions.<br \/>\nLook at this relevant video on &#8220;Understanding importance of 3D element shapes and order&#8221; <\/p>\n<p>Vigneswaran<br \/>\n<a href=\"https:\/\/ansyshelp.ansys.com\/account\/secured?returnurl=\/Views\/Secured\/main_page.html\" target=\"blank\">Ansys Help<\/a><br \/>\n<a href=\"\/forum\/categories\/rules-guidelines\" target=\"blank\">Rules &#038; Guidelines \u00d4\u00c7\u00f6 Ansys Learning Forum<\/a><\/p>\n","protected":false},"template":"","class_list":["post-211479","reply","type-reply","status-publish","hentry"],"aioseo_notices":[],"acf":[],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/replies\/211479","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\/211479\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=211479"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}