FSI - Shell elements coupling with ALE materials

Hi all,

 

 

I have tried to model a Fluid-Structure Interaction problem. This includes soil material modelled with ALE solver and a pipe modelled with shell elements. The load is an explosion shock wave.

 

When the shock comes close to the pipe, right where the CONSTRAINED_LAGRANGE_IN_SOLID is starting to work, it goes to a loophole and its timesteps start to decrease and get stuck.

 

I checked the DATABASE_FSI output and see that for one thing, this is where the coupling forces are ramping up drastically. In addition, when I check the termination info, most of the CPU clocks were used to solve the Advection Communication Algorithm.

 

I would appreciate it if anyone can help me how to overcome this or guide me to what is exactly the communication algorithm in an advection step.