{"id":392625,"date":"2024-11-04T16:32:27","date_gmt":"2024-11-04T16:32:27","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/question-about-boundary-conditions-in-ansys-mechanical\/"},"modified":"2024-11-04T16:32:27","modified_gmt":"2024-11-04T16:32:27","slug":"question-about-boundary-conditions-in-ansys-mechanical","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/question-about-boundary-conditions-in-ansys-mechanical\/","title":{"rendered":"Question about boundary conditions in Ansys Mechanical"},"content":{"rendered":"<p>&lt;p&gt;Hi,&lt;\/p&gt;&lt;p&gt;I am modelling a 3D cantilever beam with a point load applied downwards at the end of the beam. The cross-section is hollow square tube (edge length equals 10mm, thickness is uniform and equal to 1.5 mm). The length of the beam is 750mm. For boundary condition, I am using a fixed support applied at the entire cross-section face. The point load is 49.05 N.&lt;\/p&gt;&lt;p&gt;The maximum normal stress is as expected at the maximum distance from the neutral axis and equal to 1.36e8 Pa. However, when calculating analytic solution, I get sigma_max = M_max*y\/I = 49.05*0.75*(0.01\/2)\/I = 2.9e8 Pa where I = 6.33e-10 m^4. I believe my issue is direct result of applying the fixed boundary condition incorrectly, so I would appreciate some help.&lt;\/p&gt;&lt;p&gt;P.S. My mesh is well-discretized, in length direction 300 divisions, for both the outer and inner surface of cross-section there are 30 divisions on each edge. Also, my deflection at the tip matches the analytic solution.<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/11\/04-11-2024-1730737897-1.JPG\" alt=\"\" \/>&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-392625","topic","type-topic","status-publish","hentry","topic-tag-ansysworkbench-ansys-staticstructural","topic-tag-mechanical","topic-tag-student-version"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["478242","275204"],"_bbp_author_ip":["2001:6b0:1:1041:ccca:8d74:4d5:2eaa"],"_btv_view_count":["323"],"_bbp_topic_status":["unanswered"],"_bbp_topic_id":["392625"],"_bbp_forum_id":["27791"],"_bbp_engagement":["275204","478242"],"_bbp_voice_count":["2"],"_bbp_reply_count":["4"],"_bbp_last_reply_id":["392689"],"_bbp_last_active_id":["392689"],"_bbp_last_active_time":["2024-11-04 23:28:35"]},"test":"viliusvkth-se"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/392625","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\/392625\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=392625"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}