{"id":237699,"date":"2022-10-15T14:48:00","date_gmt":"2022-10-15T14:48:00","guid":{"rendered":"\/forum\/forums\/topic\/appropiate-simple-support-bcs-to-compare-solid-and-shell-model-for-sandwich\/"},"modified":"2022-10-15T14:48:00","modified_gmt":"2022-10-15T14:48:00","slug":"appropiate-simple-support-bcs-to-compare-solid-and-shell-model-for-sandwich","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/appropiate-simple-support-bcs-to-compare-solid-and-shell-model-for-sandwich\/","title":{"rendered":"Appropiate simple support BCs to compare solid and shell model for sandwich"},"content":{"rendered":"

Hi<\/p>\n

I am trying to model a sandwich plate using SOLID186 elements in Ansys Mechinal APDL. To validate my results I am comparing to a shell model which is easy to implement (reason I want to use Solid is that I am later gonna create inserts inside the sandwich). <\/p>\n

The model I am making is a square plate with a weak core and two strong faces. It is simply supported in all edges in the midplane. The pressure is a uniformly distributed pressure in the midplane of the sandwich. <\/p>\n

Right now the solid model is matching the shell model in deflection and core transverse shear. However the normal stresses in the faces are higher by a factor of 2 compared to the shell model.<\/p>\n

I think my problem might be in simulating the same simple supports for the solid model as I want the sides of the model to rotate around the midplane as they are for the shell model (see picture)<\/p>\n

<\/p>\n

Shell model – core and face are rotating perfectly around the midplane.<\/p>\n

I have tried all kinds of different approaches using CERIG and MPC184 but none have proven succesfull yet. <\/p>\n

The closest I have come is by using the CERIG command and MASS21 elements to constrain the node at the midplane (Master) to the nodes away from the midplane (slaves) in order to try constraining the slaves to rotate around the master (see picture).<\/p>\n

<\/p>\n

However, as you can see from the following results, the upper and lower edges of the sandwich are not rotating around the midplane in the same manner as for the shell model.<\/p>\n

<\/p>\n

 <\/p>\n

Do any of you know how to implement simple support BCs to a solid model in order to achieve the same behaviour as a simply supported shell model?<\/p>\n

Another point I see as problematic is that the SOLID186 element does not have rotational degrees of freedom, which I guess is the whole problem since you would need to impose the rotational DOF in some other way.<\/p>\n

I have struggled with this problem for weeks know, so all input is highly appreciated.<\/p>\n","protected":false},"template":"","class_list":["post-237699","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["264704","240"],"_bbp_author_ip":["23.220.96.181"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["645"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["237699"],"_bbp_forum_id":["27791"],"_bbp_engagement":["240","264704"],"_bbp_voice_count":["2"],"_bbp_reply_count":["4"],"_bbp_last_reply_id":["237801"],"_bbp_last_active_id":["237801"],"_bbp_last_active_time":["2022-10-17 12:05:49"]},"test":"s174188student-dtu-dk"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/237699","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\/237699\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=237699"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}