Learning Forum

[Farah]

Hi,

I'm running a 2-way FSI analysis that works fine when I use an under-relaxation factor and a very small RMS convergence target. Now, I want to run just the FEA (basically applying my desired pressure, let's say 2000 Pa), but it keeps crashing.

I've tried changing the time step and mesh, but since these settings already work in FSI, I don't think I should change them again.

Is there anything in the analysis that I can adjust to stabilize it? Perhaps a way to insert pressure as a sinusoidal function and stabilize it using settings similar to under-relaxation factor or RMS convergence but in the structural module (FEA)?

Im not sure how to set these up. anyine knows how to test? where to begin? for aorta/artery lumen 

[Ashish Khemka]

Hi,

It seems that the elements are distorting. Can you try defining large number of substeps and see at what load the model fails? Can you share the error messages you receive in the solver output?

Regards,

Ashish Khemka

[Farah]

 

Hello Ashish,

This is the error: “Solution not converged at time 0.57 (load step 1 substep 570).” 

Here is my setup:

E=0.1MPa, v=0.49, time-step= 0.001, Ens time=1.019 s,  Physics= Explicit, Element order= liner, element size= 0.00075, defeature size= 0.00030, solver= Quasi statis, type= Direct, P=-1500 Pa

Thank you in advance for your help!