Convergence problems with ANSYS Workbench SOLID 65 finite element

[Mirghani]

Hello everyone,

I am modeling the debonding between concrete and CFRP subjected to tangential loading (single shear test mode II) using ANSYS Workbench, I used the contact element with CZM created in engineering data. now I have a convergence problem in the model. as you know with workbench you can't choose the element type. you have to insert commands for Solid65. When I use the SOLID 65 concrete finite element, my models lose convergence too early. If I remove cracking and crushing capability (Suppress the commands), there are no convergence problems. Why does this happen and how can I avoid it (I need cracking and crushing)?
I already tried the following to get my model to converge:
1- Refining the mech.
2- Reducing the normal stiffness of the contact region
3- Use newton Raphson residuals.
4- Playing with steps and sub-steps.

Any help or suggestions will be highly appreciated.
Thanks in advance.

 

[beastgod]

Usually solid65 have bad convergence and requires appropriate data.
We tried to find optimal parameters for concrete and we presented our results here (in Russian)

http://cae-cube.ru/opredeleniye-optimalnykh-parametrov-rascheta-betona.html

I hope it may help you especially if you use dictionaries =).

 

[Mirghani]

thank you very much "beastgod" for your reply, really appreciate it.