{"id":163666,"date":"2021-11-02T22:46:16","date_gmt":"2021-11-02T22:46:16","guid":{"rendered":"\/forum\/forums\/topic\/assigning-hsfld242-elements-to-enclosed-surfaces-using-apdl-command-objects-in-workbench\/"},"modified":"2021-11-03T06:32:50","modified_gmt":"2021-11-03T06:32:50","slug":"assigning-hsfld242-elements-to-enclosed-surfaces-using-apdl-command-objects-in-workbench","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/assigning-hsfld242-elements-to-enclosed-surfaces-using-apdl-command-objects-in-workbench\/","title":{"rendered":"Assigning HSFLD242 elements to enclosed surfaces using APDL command objects in Workbench"},"content":{"rendered":"
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\n

Hi, <\/p>\n

I am trying to simulate force on a diaphragm that results in a change in pressure of a chamber. I am able to set up this simulation without any fluids inside of the chamber and it returns deformation results. The goal is to place a trapped fluid inside of this chamber so that the change in force on the diaphragm results in a change in pressure of the fluid as the diaphragm deforms slightly.<\/p>\n

I am now working to assign HSFLD242 elements to the inside walls of the chamber under the diaphragm. I am not familiar with APDL (trying to learn) and am attempting to add the HSFLD242 elements using a commands object in the workbench static structural tree. I have edited the code from this example<\/a> to fit my project the best that I could. Here is the edited version, where the inside walls of the chamber are named "walls'<\/p>\n

! Be careful with UNITS because of the material propertites. <<<========== <\/p>\n

! It is assumed that NO SYMMETRY effects are in this model. <\/p>\n

! <\/p>\n

fini <\/p>\n

\/prep7 <\/p>\n

*get,typemax,ETYP,,NUM,MAX ! max defined element type <\/p>\n

*get,realmax,RCON,,NUM,MAX ! max defined real constant <\/p>\n

*get,mat_max,MAT,,NUM,MAX ! max defined material <\/p>\n

*get,nodemax,NODE,,NUM,MAX ! highest numbered node in model <\/p>\n

! Create a new higher number for element type, real, and material <\/p>\n

newnode=nodemax+1000 ! number for pressure node for HSFLD242 <\/p>\n

newnumber=typemax+1 <\/p>\n

*if,realmax,ge,newnumber,then <\/p>\n

newnumber=realmax+1 <\/p>\n

*endif <\/p>\n

*if,mat_max,ge,newnumber,then <\/p>\n

newnumber=mat_max+1 <\/p>\n

*endif <\/p>\n

et,newnumber,HSFLD242 ! 3-D Hydrostatic Fluid Element <\/p>\n

keyopt,newnumber,1,0 ! UX, UY, UZ, plus HDSP at pressure node <\/p>\n

keyopt,newnumber,5,1 ! Fluid mass calculated based on the volume of the fluid element <\/p>\n

keyopt,newnumber,6,1 ! Incompressible <\/p>\n

mp,dens,newnumber,1.0e-9 ! Density of Water, kg\/mm^3\/1000 <\/p>\n

! Ignoring thermal expansion in this example <\/p>\n

! Ignoring TB,FLUID in this example <\/p>\n

r,newnumber ! Ignoring Reference pressure for compressible gas <\/p>\n

type,newnumber <\/p>\n

mat,newnumber <\/p>\n

real,newnumber <\/p>\n

! <\/p>\n

cmsel,s,walls ! Select nodes on interior <\/p>\n

esln ! Select elements that touch these nodes <\/p>\n

n,newnode,0,0,0.07 ! Pressure node at 0,0,400 (automatically moved to centroid?) <\/p>\n

ESURF,newnode ! ESURF HSFLD242 elements over solid element faces <\/p>\n

! Extra node “newnode” with ESURF with HSFLD242 <\/p>\n

allsel <\/p>\n

fini <\/p>\n

\/solu ! return to solving <\/p>\n

<\/p>\n<\/p>\n

When I hit solve, the program does not converge and it returns errors. Any help on how to assign the HSFD242 elements to this would be appreciated, I can share more from the workbench project if needed.<\/p>\n","protected":false},"template":"","class_list":["post-163666","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_author_ip":[""],"_bbp_view_count":["296"],"_bbp_likes_count":["0","0"],"_bbp_forum_subforum_count":["0"],"_btv_view_count":["475"],"_bbp_subscription":["238845"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["163666"],"_bbp_forum_id":["27791"],"_bbp_engagement":["58821","238845"],"_bbp_voice_count":["2"],"_bbp_reply_count":["1"],"_bbp_last_reply_id":["196689"],"_bbp_last_active_id":["196689"],"_bbp_last_active_time":["2021-11-03 06:32:50"]},"test":"joekerchrams-colostate-edu"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/163666","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\/163666\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=163666"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}