Hello, 

I am using C3D8RPT elements in my model to be able to have pore pressure and temperature degrees of freedom. According to ABAQUS user assistance, while using C3D8RPT and XFEM in model, we can't define temperature as a predefined field and it should be defined as boundary condition. My model is a cube with dimensions 0.3*0.3*0.3 and I define a temperature boundary condition around the cube and then I run geostatic step so the model will reach steady state condition and at the end of the step whole model will have same temperature as boundary. Then I use *cflux to get heat from the middle of the model but it gives error " too many attempts" after temperature changes from 200 to 199.8 and exits and I'm using 0.005 for the element size. I tried different fluxes but it still gives error after some temperature difference. When I'm using bigger model size like 20*20*20 I'm not having the error but when I want to model a 0.3*0.3*0.3 cube it gives error. How can I fix this error? Or is there a different way to simulate temperature distribution in a small porous rock sample?

Any help is appreciated.