Algorithm for viscoplastic FEA analysis

[usan]

I am trying to solve a FEA problem with viscoplastic strains using the fully explicit method described in Zienkiewicz, Vol 2, Chap. 7. It is basically a Euler method of solving the nonlinear equations, and I am having convergence problems. I cannot use the implicit method because the Jacobian matrix cannot be determined with the material model I have. Does anybody know of a better algorithm to solve such problems? Thanks.

 

[mjie]

You want to write a program by yourself? That may take long time. I think you can try LSDYNA. The program uses explicit algorithm and has several viscoplastic material model.

mjie

 

[usan]

Unfortunately I cannot use a canned program, because I am doing some modeling that is integral with the FEM procedure. So yes, I do have to write my own program. Any suggestions?

Santhosh

 

[mjie]

LSDYNA provides user-defined material subroutine, through which you can couple your own material model into the program. In this way you can save a lot of time by avoiding to deal with detailed FEM algorithm.

mjie