Element distortion in 3D machining

[Vxxxxx]

Hi everyone, Im trying to realise ultrasonic machining of a certain material, but I encountered element distortion problem for my 3D simulation.
I had no problem on 2D simulation, and I used the same material properties for 3D.

Drucker prager plasticity
shear damage
general contact
dynamic,temp-disp, explicit 0.00001s timestep
ran on 12 cores
100 output, errors occurred at 4/100 output
element size, try different dimensions, still failed.
tried different speed as well.

I have tried for months, would be grateful if anyone could shed some lights. thank you.

 

[FEA way]

Is element deletion enabled ? Maybe you should adjust the damage criteria. Take a closer look at the distorted regions, run animation and try to figure out what causes this distortion.

 

[Vxxxxx]

Hi FEA way, element deletion is enabled. Will surface-to-surface contact help? I tried using it before, but it takes forever to run.
As for the damage criteria, I ran before with high/low fracture strain/fracture energy but i get the same results.
I succeeded once with explicit step(without temperature in the equation).

 

[FEA way]

Usually, general contact is the best choice (especially in Explicit) but you can try changing it as there are always some exceptions. Apart from that, try locally refining the mesh and check the distortion control settings. Also, consider using ALE adaptive mesh.

 

[Vxxxxx]

Noted, I will try ALE to see if there is any differnce. Thank you FEA wa.