{"id":32659,"date":"2019-01-15T06:13:58","date_gmt":"2019-01-15T06:13:58","guid":{"rendered":"\/forum\/forums\/topic\/how-to-solve-conflicting-dof-constraints-on-hemispherical-shell-problem\/"},"modified":"2019-01-15T06:13:58","modified_gmt":"2019-01-15T06:13:58","slug":"how-to-solve-conflicting-dof-constraints-on-hemispherical-shell-problem","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/how-to-solve-conflicting-dof-constraints-on-hemispherical-shell-problem\/","title":{"rendered":"How to solve conflicting DOF constraints on hemispherical shell problem?"},"content":{"rendered":"<p>&nbsp;When I use Ansys analyzes the classical benchmark, hemispherical shell problem as shown in the first picture below, I got an error shown as the second picture below.<\/p>\n<p><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/9353ff24-85bd-4561-aa7d-a9d500f905a9\/836d946b-c488-4d35-89d6-a9d6005f09eb_screen-shot-2019-01-14-at-10.44.56-pm.jpg?width=690&amp;upscale=false\" alt=\"Hemispherical shell schematics\"><\/p>\n<p><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/9353ff24-85bd-4561-aa7d-a9d500f905a9\/c20cf7d0-1eea-4b20-8a2a-a9d6005fd4e4_screen-shot-2019-01-14-at-4.50.57-pm.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n<p><\/p>\n<p>The displacement boundary conditions and the force boundary conditions are shown in the following picture. More specifically, the displacement boundary conditions are applied as,<\/p>\n<p><\/p>\n<p>the left boundary is fixed with translation in y-direction, i.e., u_y = 0, and the rotations around x and z-axis are zero, i.e., r_x = r_z = 0;<\/p>\n<p><\/p>\n<p>the right boundary is fixed with translation in x-direction, i.e., u_x = 0, and the rotations around y and z-axis are zero, i.e., r_y = r_z = 0;&nbsp;<\/p>\n<p><\/p>\n<p>the lower-left corner point is used to remove the rigid body motion in z-direction, i.e., u_z = 0.<\/p>\n<p><\/p>\n<p>The force boundary conditions are specified at node&nbsp;1 and node 2 as shown in the following picture, i.e., a constant force along x-direction&nbsp;at node 1, and a constant force along y-direction at node 2.&nbsp;<\/p>\n<p><\/p>\n<p>Theoretically, there is no translation displacement boundary condition applied at node 1 along x-direction&nbsp;and no translation displacement boundary condition applied at node 2 along y-direction. Therefore, there should not be conflicting DOF between the displacement constraints and the loading.<\/p>\n<p><\/p>\n<p>Is anybody know how should I solve this conflict but still apply the boundary conditions correctly? THanks very much.<\/p>\n<p><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/9353ff24-85bd-4561-aa7d-a9d500f905a9\/676be10e-b9f2-4138-a2df-a9d600604ad9_ansys.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n","protected":false},"template":"","class_list":["post-32659","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["4831"],"_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","0","0","0","0"],"_btv_view_count":["1964"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["32659"],"_bbp_forum_id":["27791"],"_bbp_engagement":["160648","161739"],"_bbp_voice_count":["2"],"_bbp_reply_count":["11"],"_bbp_last_reply_id":["75003"],"_bbp_last_active_id":["75003"],"_bbp_last_active_time":["2019-01-15 18:34:12"]},"test":"zhihuizou1988"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/32659","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\/32659\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=32659"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}