AN EXPLICIT FINITE ELEMENT MODEL TO STUDY THE INFLUENCE OF RAKE ANGLE ON THE DISCONTINUOUS CHIP FORMATION DURING ORTHOGONAL METAL CUTTING

摘要

Understanding the tribological aspects of machining processes are essential for increasing the dimensional accuracy and surface integrity of products, as well as gaining a better control of tool wear, chip handling and power consumption. The objective of this investigation is to develop numerical models that accurately predict the chip formation and stress profiles in the work-piece during orthogonal metal cutting using the explicit finite-element method (FEM). In our simulations, a damage material model was utilized to capture the work-piece chip separation behavior and the simultaneous breakage of the chip into multiple fragments. In the simulation, the rigid steel cutter of different rake angles was moved at different velocities against a stationary aluminum work-piece at constant friction for a cutting depth of 1 mm. Overall, the results indicate that the explicit FEM is a powerful tool for simulating metal cutting and discontinuous chip formation. The rake angle had a significant effect on the formation of chip during metal cutting. The formation of discontinuous chip along the contact interface was hypothesized to be due to the internal crack initiation and propagation in front of the tool and above the cutting edge, rather than from the free surface.