{"id":39954,"date":"2020-01-05T18:00:29","date_gmt":"2020-01-05T18:00:29","guid":{"rendered":"\/forum\/forums\/topic\/not-enough-constraints-problem-with-the-excavators-boom\/"},"modified":"2020-01-05T18:00:29","modified_gmt":"2020-01-05T18:00:29","slug":"not-enough-constraints-problem-with-the-excavators-boom","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/not-enough-constraints-problem-with-the-excavators-boom\/","title":{"rendered":"&#8220;Not enough constraints&#8230;&#8221; problem with the excavator&#8217;s boom"},"content":{"rendered":"<p>Hi everyone! I&#8217;m a mechanical engineering student and I&#8217;ve problem with this warning.<\/p>\n<p><\/p>\n<p>&#8220;not enough constraints appear to be applied to prevent rigid body motion. this may lead to solution warnings or errors. check results carefully.&#8221;<\/p>\n<p><\/p>\n<p>The model is the<em>&nbsp;<span style=\"text-decoration: underline;\">boom of an excavator<\/span><\/em>: in target D and E there are the connections to an hypothetical chassis; in target A there is the pin which connects the piston and the boom and permits the rotation. I put the constraints in order to create a three-hinged arch, so I chose the&nbsp;<strong>cylindrical supports<\/strong> to recreate the revolute joints (target A, D, E in the figure), blocking axial and radial directions and freeing the tangential one, but it didn&#8217;t work: &#8220;Not enough constraints &#8230;&#8221;<\/p>\n<p><\/p>\n<p>So I&nbsp;tried another way: I created two cylindrical coordinate systems, one in target D the other in target E, and I put&nbsp;<strong>diplacements<\/strong> like in the figure below, blocking the translations and freeing the rotation, but the problem persists.<\/p>\n<p><\/p>\n<p>Can anyone help me? What&nbsp;should&nbsp;i do to solve the warning?<img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/82c05be6-23fa-4b30-b087-ab3901164795\/ef88e891-a9f1-4e55-ba16-ab390128930e_esc.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n","protected":false},"template":"","class_list":["post-39954","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["12133"],"_bbp_old_topic_author_name_id":["Anonymous"],"_bbp_old_is_topic_anonymous_id":["false"],"_bbp_old_closed_status_id":["publish"],"_bbp_author_ip":[null],"_bbp_old_sticky_status_id":["normal"],"_bbp_likes_count":["0"],"_btv_view_count":["1405"],"_bbp_subscription":["246279"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["39954"],"_bbp_forum_id":["27791"],"_bbp_engagement":["240","171962"],"_bbp_voice_count":["2"],"_bbp_reply_count":["5"],"_bbp_last_reply_id":["102159"],"_bbp_last_active_id":["102159"],"_bbp_last_active_time":["2020-01-09 02:42:37"]},"test":"levinz95"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/39954","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\/39954\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=39954"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}