Positive/negative sign of cutting force

[Vxxxxx]

Hi, I have a question regarding the positive/negative sign of cutting force in 2D cutting simulation.

I set the tool as rigid body and give a velocity on a reference point at the tip of the tool. The cutting force in X direction should be positive as it is the reaction force from the workpiece acting on the tool. However, ABAQUS always gives me negative values of cutting force, which I do not understand why. It would be great if someone could provide some answers. Thank you.

 

[FEA way]

The reaction force must oppose the contact forces. You will see this if you make a simple test with two blocks, one moving towards the other. Here's how the forces look like (I separated the parts artificially but in the analysis they were in contact):

 

[Vxxxxx]

Hi FEA way, thank you for your reply.

From what i know, Assuming the block on the right is my tool(moving towards left direction), and the block on the left is my workpiece(which is stationary),therefore the force to the right is contact force, while the the force to the left is the reaction force. Am I right?

Thank you.

 

[FEA way]

In the attached picture, multiple (mostly) red arrows represent contact forces on each block. The orange arrow pointing to the right is just a prescribed velocity BC. But the reaction force at that reference point will also be pointing in the same direction. I should add that the left block is fixed while the right one is moving towards it.

 

[Vxxxxx]

Noted. Thank you very much for your explanation, FEA way.