Abaqus Machining Simulation: Highly distorted element on breaking chips

[MF Afif]

Dear fellow

I have successfully run the simulation for machining in Abaqus explicit. In one case of the simulation, the solving process stopped because there are highly distorted elements which are found in the chip after it completely separated from the remaining material (debris). These elements (on the debris) was very far away to the cutting process, but I think the solver still did the calculation there.

What are the strategies to overcome this?
Probably delete the elements (chip) after it experience breakage? How to implement this?

Thanks

Afif

 

[FEA way]

Which modeling techniques and material damage models are you using for this simulation ?

 

[MF Afif]

This is the detail of the simulation that I used:

1. The machining setting is orthogonal cutting model with 2D plane strain analysis on Explicit dynamics
2. The simulation is performed in microscale. The workpiece is 1000 micron in length. The uncut chip thickness is 50 micron.
2. Tool is regarded as rigid
3. Workpiece material is modelled with Johnson-Cook plasticity model and Johnson-Cook Damage model and damage evolution criteria
4. Mesh size is 5 micron. The element type is 2D explicit and mesh deletion is allowed. The Arbitrary Lagrangian-Eulerian (ALE) is used on the model
5. I have request the STATUS on the field request output
6. Surface-to-surface contact is applied on the tool and workpiece with coefficient of friction of 0.3

Some of the analysis can be solved and the results can be obtained. However, for a particular parameters applied, this distortion problem occurs.
It happened on the debris (chip breakage), not the currently cut material. So, it should not affect the simulation, hence I think I could just delete it.
Is this true? Any way to implement this?

Thanks a lot

 

[FEA way]

I would have to see that to say more but it can be a problem with the material damage properties. It might be also good to check the contact definition (if it properly accounts for the surface erosion), try without ALE and refine the mesh manually.