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New Ansys user - Unconverged Solution Problem

New Ansys user - Unconverged Solution Problem

New Ansys user - Unconverged Solution Problem

(OP)
Hi all, I'm a new member to the forum and I've lurked here for a while as I've found solutions to my previous issues deep within the forum. However, I have an issue with my current ANSYS problem (I'm also a rather green ANSYS user). I'm working in ANSYS APDL 14.0 with a 2D axisymmetric model.

I'm using Plane13 elements to represent magnetic coils that transfer load to a structure made of Plane82 elements. Everything is bonded, with no contact elements, mesh size is 1mm.

Since I'm relatively new to ANSYS in general I am having trouble figuring out how to solve this. Any help would be greatly appreciated.

I'm running into this convergence problem as stated by ANSYS:

CODE

*** WARNING ***                         CP =     298.992   TIME= 09:15:03
 There are 1 small equation solver pivot terms.                          
     DISP CONVERGENCE VALUE   = 0.3883E-02  CRITERION= 0.7839E-03
    EQUIL ITER   6 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.5596E-03
     FORCE CONVERGENCE VALUE  = 0.5743E+06  CRITERION=  928.3    
 *** WARNING ***                         CP =     302.798   TIME= 09:15:05
 There are 3 small equation solver pivot terms.                          
     DISP CONVERGENCE VALUE   = 0.3965E-01  CRITERION= 0.7839E-03
    EQUIL ITER   7 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.3232E-02
 *** ERROR ***                           CP =     304.155   TIME= 09:15:06
 Negative Jacobian 2D.                                                   
 *** WARNING ***                         CP =     304.155   TIME= 09:15:06
 The unconverged solution (identified as time 8 substep 999999) is       
 output for analysis debug purposes.  Results should not be used for     
 any other purpose.                                                      
         R E S T A R T   I N F O R M A T I O N
 REASON FOR TERMINATION. . . . . . . . . .ERROR IN ELEMENT FORMULATION 



RE: New Ansys user - Unconverged Solution Problem

Hello,

I am using Ansys for structural problems, different from your field.
But about your problem, I think you should pay attention to the type of elements that you are using in the same model. Plane13 is a 4-node element while Plane82 has 8 nodes. How we can match 4 nodes to 8 nodes in boundaries? Also Plane82 has just 2-degrees of freedom in each node while it could be 4 degrees for the Plane13, in fact we can not match theses two elements in a common joint without coordinating DOFs. If you care about these matters, you may solve your problem.

Hassan

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