{"id":162210,"date":"2023-01-25T07:34:37","date_gmt":"2023-01-25T07:34:37","guid":{"rendered":"\/knowledge\/forums\/topic\/how-can-i-specify-acceleration-at-a-node-could-i-use-the-big-mass-method\/"},"modified":"2023-07-31T12:36:49","modified_gmt":"2023-07-31T12:36:49","slug":"how-can-i-specify-acceleration-at-a-node-could-i-use-the-big-mass-method","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/how-can-i-specify-acceleration-at-a-node-could-i-use-the-big-mass-method\/","title":{"rendered":"How can I specify acceleration at a node? Could I use the ‘big mass method’?"},"content":{"rendered":"

Yes, it could be done by the ‘big mass method.’ A demonstration of the big mass method is given below. The final plot in the time-history postprocessor shows that a unit acceleration time history has been produced at the beam support location. \/prep7 et,1,4 r,1,.1,.01,.01,.05,.05 mp,ex,1,1e7 mp,dens,1,.00025 n,1 n,11,50 fill e,1,2 *repeat,10,1,1 et,2,21 r,2,,1250 ! big mass in y direction only type,2 real,2 e,1 d,1,all ddele,1,uy ! constrain all but y direction fini \/solu antype,trans omega=100 ! 100 radians\/sec *do,tval,.001,.1,.001 f,1,fy,1250*sin(omega*tval) ! to produce a(y) = 1*sin(wt) time,tval solve *enddo fini \/post26 nsol,2,1,uy deriv,3,2,1 deriv,4,3,1 plva,4 ! verify s<\/p>\n","protected":false},"template":"","class_list":["post-162210","topic","type-topic","status-publish","hentry","topic-tag-4706","topic-tag-apply-acceleration-at-node","topic-tag-big-mass-method","topic-tag-mechanical-apdl-f-ansys","topic-tag-modal-harmonic-response","topic-tag-structural-dynamics","topic-tag-structural-mechanics"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t