{"id":359794,"date":"2024-04-01T11:14:17","date_gmt":"2024-04-01T11:14:17","guid":{"rendered":"\/forum\/forums\/topic\/probem-with-modal-analysis\/"},"modified":"2024-04-01T11:14:17","modified_gmt":"2024-04-01T11:14:17","slug":"probem-with-modal-analysis","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/probem-with-modal-analysis\/","title":{"rendered":"Probem with modal Analysis"},"content":{"rendered":"<p>Hello,<\/p>\n<p>I&#8217;m having some issues with a modal analysis of a full ship model in APDL. The model has all panels and stiffeners in it, when I run the modal analysis I get the first six modes equal to zero which makes sense as it is a free-free model but then the following modes are not the global modes of the entire ship but just of singular panels.&nbsp;Is there a way to eliminate the local modes? I know in FEMAP\/Nastran this would be done with the ASET constraint using master nodes but I don&#8217;t know how to do it in APDL?<\/p>\n<p>Secondly, if I want to use FLUID30 elements to simulate the water around the ship is there a way to just overlay them onto the elements of the ship using something like the ESURF command? My idea was something along the line of:&nbsp;<\/p>\n<p>et,5,30&nbsp;<br \/>mp,dens,5,1250<br \/>mat,5<br \/>esel,s,cent,z,0,3800<br \/>esurf&nbsp;<\/p>\n<p>But ESURF does not work here as it only works for line and area elements, is there another way? Any help is much appreciated, thanks in advance!&nbsp;<\/p>\n","protected":false},"template":"","class_list":["post-359794","topic","type-topic","status-closed","hentry","topic-tag-Modal_Analysis-1","topic-tag-ansys-apdl","topic-tag-ansys-mapdl-1","topic-tag-apdl"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["342643","58821"],"_bbp_author_ip":["23.206.193.154"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["358"],"_bbp_topic_status":["unanswered"],"_bbp_topic_id":["359794"],"_bbp_forum_id":["27791"],"_bbp_engagement":["58821","342643"],"_bbp_voice_count":["2"],"_bbp_reply_count":["5"],"_bbp_last_reply_id":["360278"],"_bbp_last_active_id":["360278"],"_bbp_last_active_time":["2024-04-03 12:38:40"]},"test":"l-p-p-ackermannstudent-tudelft-nl"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/359794","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\/359794\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=359794"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}