{"id":434788,"date":"2025-06-19T08:00:31","date_gmt":"2025-06-19T08:00:31","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/contact-forces-not-making-sense-to-me-at-least\/"},"modified":"2025-06-19T08:00:31","modified_gmt":"2025-06-19T08:00:31","slug":"contact-forces-not-making-sense-to-me-at-least","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/contact-forces-not-making-sense-to-me-at-least\/","title":{"rendered":"Contact Forces not making sense (to me at least)"},"content":{"rendered":"<p>&lt;p&gt;Hello,&lt;\/p&gt;&lt;p&gt;I&acute;m doing a static simulation in a rack, where the load of 10,000N is applied on three faces, like this:&lt;\/p&gt;&lt;p&gt;<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2025\/06\/19-06-2025-1750316831-mceclip1.png\" width=\"805\" height=\"294\" \/>&lt;\/p&gt;&lt;p&gt;<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2025\/06\/19-06-2025-1750317547-mceclip3.png\" width=\"813\" height=\"458\" \/>&lt;\/p&gt;&lt;p&gt;In six points there should be a column holding everything together but I used fixed supports, just for simplicity (the whole structure is composed of 4 levels, with the same geometry). Everything will be weld together so I used bonded contacts.&lt;\/p&gt;&lt;p&gt;<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2025\/06\/19-06-2025-1750317444-mceclip2.png\" width=\"934\" height=\"526\" \/>&lt;\/p&gt;&lt;p&gt;Now, when I want to check the force reaction in the contact area there are some odd things that I can&acute;t seem to understand:&lt;\/p&gt;&lt;p&gt;The force when extracted from either the Target or Contact have the same direction; the Y component is the only opposite but twice the value. The rest of the contacts do have opposite directions, not exactly the same components though.<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2025\/06\/19-06-2025-1750318366-mceclip4.png\" width=\"1009\" height=\"426\" \/><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2025\/06\/19-06-2025-1750318897-mceclip5.png\" width=\"506\" height=\"172\" \/>&lt;\/p&gt;&lt;p&gt;I thought the contact forces should be opposite, I mean, at least in this case where two planar faces are in contact and both are not extender in all the solid.&lt;\/p&gt;&lt;p&gt;Initially I used &#8220;Augmented Lagrange&#8221;, then changed to &#8220;program controlled&#8221; (which uses MPC I think).&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2025\/06\/19-06-2025-1750320014-mceclip6.png\" \/>&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-434788","topic","type-topic","status-publish","hentry","topic-tag-contact","topic-tag-mechanical","topic-tag-static-structural"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_forum_id":["27791"],"_bbp_topic_id":["434788"],"_bbp_subscription":["470439","99"],"_bbp_author_ip":["46.25.71.106"],"_bbp_last_reply_id":["434894"],"_bbp_last_active_id":["434894"],"_bbp_last_active_time":["2025-06-20 09:24:35"],"_bbp_reply_count":["2"],"_bbp_reply_count_hidden":["0"],"_bbp_voice_count":["2"],"_bbp_engagement":["470439","99"],"_btv_view_count":["238"],"_bbp_topic_status":["unanswered"]},"test":"lvelasquezzeleros-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/434788","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\/434788\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=434788"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}