Grain shape-protrusion-based modeling and analysis of material removal in robotic belt grinding

The accurate prediction of material removal (MR) remains a persistent challenge in the field of robotic belt grinding, particularly with the consideration of the stochastic nature of abrasive grains. Starting from the characteristics that abrasive grains with different shapes participate in grinding, this work presents a novel MR model that extends from microscopic grain-workpiece interaction to macroscopic wheel-curved surface contact. Specifically, the irregular shapes of single abrasive grains are generalized into four typical types, namely, semi-sphere, cone, equilateral-triangular pyramid, and square pyramid. Based on the effective abrasive grains determined by stochastic grain protrusion heights, the microscopic contact force and material removal volume shared by different effective individual abrasive grains are modeled and analyzed subsequently. Together with the macroscopic contact pressure solved by the Hertzian contact theory, the material removal model is derived by considering the geometrical characteristics of different-shaped abrasive grains. Finally, the grinding experiments on the Ti-6Al-4V test block and aero-engine blade were conducted under controllable grinding parameters, through which the effectiveness and applicability of the proposed model were validated, and the material removal characteristics with different structured abrasive belts were investigated.