I am trying to simulate a shear process for cutting a circular rod, as follow: I have 2 discrete rigid bodies (blades) and 1 deformable body (rod):

 After defining the material properties using Johnson-Cook Damage, and Plastic with the Johnson-Cook hardening as below:

I am using Explicit procedure, and defined the interaction as 1- General Contact (Explicit) with Friction factor, and also "Surface to Surface contact (Explicit)" interaction between the blades and the Working_node surface on the rod as will be cut when come into contact with the blade. 

I've meshed the rod with Sweep method and Hex Shape, and Explicit-Linear-Reduced integration type of element and toggle on the deletion, as follow:
 

I've partitioned those areas that will be touch the blades so I do refined mesh to decrease the computation time and accuracy of the simulation. However, when I ran the simulation, I can see that other parts of the rod that are not intended to be affected by the process were cut as for example shown below:
 

I've tried to refine the mesh but still seeing the same problem, and couldn't figure out yet why this is happening! 
 

I appreciate any thought on how to have cut only on those intended regions?