


{"id":364385,"date":"2024-04-26T11:52:22","date_gmt":"2024-04-26T11:52:22","guid":{"rendered":"\/forum\/forums\/topic\/nodal-moment-or-force-reaction-in-a-tube-with-harmonic-excitation\/"},"modified":"2024-04-26T11:52:22","modified_gmt":"2024-04-26T11:52:22","slug":"nodal-moment-or-force-reaction-in-a-tube-with-harmonic-excitation","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/nodal-moment-or-force-reaction-in-a-tube-with-harmonic-excitation\/","title":{"rendered":"nodal moment or force reaction in a tube with harmonic excitation"},"content":{"rendered":"<p>Hi!<\/p>\n<p>I have an easy system (s. fig.) which is a harmonic torsional excited water filled tube.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" title=\"System\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2024\/04\/26-04-2024-1714132195-Screenshot 2024-04-26 133323.png\" alt=\"\" width=\"740\" height=\"464\"><\/p>\n<p>Now I want to extract and average the nodal forces to calculate the torsional moment around the tube axis in a user defined cross-section (component, sliced like a salami \ud83d\ude42 ) in the pipe wall via APDL Postcommands. I tried the following but it didn&#8217;t work out:<\/p>\n<p>&#8230;<\/p>\n<p>direc_axial &nbsp; &nbsp; = &#8216;Y&#8217;<br \/>direc_trans_1 &nbsp; = &#8216;Z&#8217;<br \/>direc_trans_2 &nbsp; = &#8216;X&#8217;<\/p>\n<p>CMSEL,S,ebene !Auswahl der Ebene als Komponente<br \/>*GET,n_nodes,NODE,,count !Anzahl der Knoten in der Ebene<br \/>*DIM,calc_array,ARRAY,n_nodes,13 !Init Array f&uuml;r fl&auml;chengewichtete R\/Im des Drucks und der Fl&auml;che (n_nodes x 2)<\/p>\n<p>set,1,i,,IMAG<br \/>next_node = 0<br \/>*DO,j,1,n_nodes,1<br \/>next_node = ndnext(next_node)<\/p>\n<p>calc_array(j,1) = ARNODE(next_node)<\/p>\n<p>!Rotation um Rohrachse<br \/>*GET,r_trans1,NODE,next_node,LOC,direc_trans_1<br \/>*GET,r_trans2,NODE,next_node,LOC,direc_trans_2<br \/>r_abs = sqrt(r_trans1**2 + r_trans2**2)&nbsp;<br \/>u_rot = 1\/r_abs*(-r_trans2*u_trans1 + r_trans1*u_trans2) !ACHTUNG: VZ in der Klammer ist entscheidend f&uuml;r die Phase<br \/>calc_array(j,11) = u_rot*calc_array(j,1)<br \/>!Moment um Rohrachse<br \/><strong>*GET,f_trans1,NODE,next_node,RF,direc_trans_1<\/strong><br \/><strong>*GET,f_trans2,NODE,next_node,RF,direc_trans_1<\/strong><br \/><strong>f_rot = 1\/r_abs*(-r_trans2*f_trans1 + r_trans1*f_trans2)<\/strong><br \/><strong>m_rot = f_rot*r_abs<\/strong><br \/>calc_array(j,13) = m_rot*calc_array(j,1)<br \/>*ENDDO<\/p>\n<p>&#8230;<\/p>\n<p>Actually it thought that this should be a hard task&#8230; but it turns out to be. Does anybody has some suggestions for an alternative workflow??<\/p>\n<p>Greetings!!!<\/p>\n<p>Christian<\/p>\n","protected":false},"template":"","class_list":["post-364385","topic","type-topic","status-closed","hentry","topic-tag-ansys-mechanical-apdl","topic-tag-harmonic-acoustics","topic-tag-harmonic-analysis"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["170334","20905"],"_bbp_author_ip":["23.218.248.135"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["333"],"_bbp_topic_status":["unanswered"],"_bbp_topic_id":["364385"],"_bbp_forum_id":["27791"],"_bbp_engagement":["20905","170334"],"_bbp_voice_count":["2"],"_bbp_reply_count":["1"],"_bbp_last_reply_id":["364705"],"_bbp_last_active_id":["364705"],"_bbp_last_active_time":["2024-04-29 13:44:36"]},"test":"christijaaan"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/364385","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\/364385\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=364385"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}