Simulation of Hexa-Octahedral Diamond Grain Cutting Tests Using the SPH Method

Single grain cutting tests are an important basic tool in understanding complex grinding processes. Simulations offer additional insight into important process data and can reduce the overall number of required experiments.Cutting simulations with FE Methods have problems arising from large deformations at the chip root and negative rake angles of the diamond grain. Those problems can be overcome using meshfree methods, but with the additional difficulties of contact modeling and the enforcement of boundary conditions. In this work, a Smoothed Particle Hydrodynamics (SPH) Method is used to model the cutting behavior of single hexa-octahedral diamond cutting grains. The material behavior at low cutting depths is characterized using experimental data and simulations of micro-Vickers indenter tests.The simulations show the influence of the yaw and rake angle on the cutting and passive forces as well as the ratio of chip and burr generation. Both the cutting and the passive forces show good accordance with the experimental data. The burr generation is still overestimated due to the lack of a physical failure criterion in the SPH-method. Difficult to predict effects like the generation of a stagnant zone of workpiece material moving in front of the diamond grain at the chip root are reproduced as well. This work shows the advantages of using a meshfree method in areas were classical FE-methods have difficulties.