{"id":33384,"date":"2019-02-19T07:28:50","date_gmt":"2019-02-19T07:28:50","guid":{"rendered":"\/forum\/forums\/topic\/ansys-contact-problems\/"},"modified":"2019-02-19T07:28:50","modified_gmt":"2019-02-19T07:28:50","slug":"ansys-contact-problems","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/ansys-contact-problems\/","title":{"rendered":"ANSYS Contact problems"},"content":{"rendered":"

Hi, I am doing a nonlinear analysis on a brick wall in static structural analyses. the wall contain solid (solid65) and contact (conta174, targe170) elements.<\/p>\n

two types of contact are used (each contact surface is defined by 2 types) Bonded and Frictional (to include the friction coefficient). also the bonded contacts are combined with CZM (Separation-Distance based Debonding) to include the separation.<\/p>\n

When I solved the model the following errors and warnings occurred in solver output: <\/p>\n

WARNINGS                     <\/p>\n

 1- Element shape checking is currently inactive.  Issue SHPP,ON or SHPP,WARN to reactivate, if desired. <\/p>\n

 2-  Real constant 1 referenced by at least element types 1 and 2.<\/p>\n

 3-  Material number 2528 (used by element 136227 ) should normally have at least one MP or one TB type command associated with it.  Output of  energy by material may not be available.                                <\/p>\n

4-  ANSYS has found the contact pairs have similar mesh patterns which can cause over-constraint.  ANSYS will deactivate the current pair and keep its companion pair.                                                     <\/p>\n

5- Maximum friction coefficient 0.7 is defined in the model.  Switch to the unsymmetrical solver (NROP,UNSYM) instead if convergence difficulty is encountered.                                                         <\/p>\n

6-  Coefficient ratio exceeds 1.0e8 – Check results.                        <\/p>\n

7- Contact element 84257 (real ID 1322) status changes abruptly from contact (with target element 84191) -> no-contact.                      <\/p>\n

8- Contact element 47726 (real ID 310) status changes abruptly.  We assume that the status of this element (and possibly others) represents a spurious contact.   <\/p>\n

9- The geometrical penetration may be too large.  Increase pinball if it  is a true geometrical penetration.  Decrease pinball if it is a false one.             <\/p>\n

10-  The geometrical gap may be too large.  Increase pinball if it is a true geometrical gap.  Decrease pinball if it is a false one.       <\/p>\n

11-  The unconverged solution (identified as time 1 substep 999999) is  output for analysis debug purposes.  Results should not be used for  any other purpose.                                                 <\/p>\n

ERRORS <\/p>\n

1- The value of UZ at node 28466 is 5980424.25.  It is greater than the current limit of 1000000 (which can be reset on the NCNV command).   This generally indicates rigid body motion as a result of an unconstrained model.  Verify that your model is properly constrained.   <\/p>\n

 2-  If one or more parts of the model are held together only by contact verify that the contact surfaces are closed.  You can check contact status in the SOLUTION module for the converged solutions using CNCHECK.                                                                <\/p>\n

3-  Rigid body motion can also occur when net section yielding has occurred resulting in large displacements for small increments of load  <\/p>\n

 or when buckling has occurred.  You can plot the time history curve for node 28466 in the UZ direction to check for stiffness (slope of     <\/p>\n

 the curve) approaching zero. <\/p>\n

I tried for many moths to solve those problems but I didn’t find the solution. Knowing that when I suppress the CZM the model converge without problem but the results go so far compared to experimental. When I include the CZM the model diverge but the results obtained are close to experimental.<\/p>\n

the following messages occurred in workbench: <\/p>\n

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

<\/p>\n

Any help would be very appreciated<\/p>\n","protected":false},"template":"","class_list":["post-33384","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["5556"],"_bbp_old_topic_author_name_id":["Anonymous"],"_bbp_old_is_topic_anonymous_id":["false"],"_bbp_old_closed_status_id":["publish"],"_bbp_author_ip":[null],"_bbp_old_sticky_status_id":["normal"],"_bbp_likes_count":["0","0","0","0","0"],"_btv_view_count":["8891"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["33384"],"_bbp_forum_id":["27791"],"_bbp_engagement":["897","159332","161677","189505","262268"],"_bbp_voice_count":["5"],"_bbp_reply_count":["9"],"_bbp_last_reply_id":["150127"],"_bbp_last_active_id":["150127"],"_bbp_last_active_time":["2021-04-20 15:38:29"]},"test":"amin"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/33384","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\/33384\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=33384"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}