Stress concentration and element distortion

[Vxxxxx]

Hi, I am trying to simulation turning of a certain material and I have encountered two problems.

1. There are elements where stresses are concentrated on elements in contact with the tip of the tool
2. There are still some minor element distortion even though I have activated contact inclusion to prevent elements from penetrating each other inside the workpiece.

I have tried all kinds of hourglass control and all of the results show stress concentration. Also, element distortion still exists.



Would highly appreciate if anyone could provide some guidance. Thank you.

 

[FEA way]

Do you use damage criterion and element deletion ? Have you tried with ALE or adaptive remeshing ?

 

[SWComposites]

Why would you expect there is NOT a stress concentration?

 

[Vxxxxx]

Hi FEAway, I used drucker prager model and shear damage criteria. As for ALE/adaptive remeshing, I was told that ALE is not suitable for machining simulation. What do you suggest or do you need more information about my model? Thank you.

 

[Vxxxxx]

Hi @SWComposites,sorry if I brought any misunderstanding. What I meant was concentration of stress only on one of two particular elements as shown in the figure before.



Thank you.

 

[SWComposites]

Wouldn’t it be more appropriate to model it as a fracture mechanics problem? Don’t see how you will get a chip to separate with the current approach.

 

[Mustaine3]

>2. There are still some minor element distortion even though I have activated contact inclusion to prevent elements from penetrating each other inside the workpiece.

Did you include the interior faces of the part into General Contact? By default only the exterior faces are used.

 

[Vxxxxx]

@SWComposites I am not sure how to model it as a fracture mechanics problem but I used shear criterion to define damage initiation.

 

[Vxxxxx]

@Mustaine3 yes, I have included all elements of the cutting layer