Grinding stress of different diamond abrasive grains based on the variable cross-section beam

The bonding strength of abrasive grain on the brazed diamond grinding wheel is the main factor affecting the performance of the grinding wheel. To analyze the influence of different grain sizes and shapes on the grinding stress distribution, the grain wear form and the strength of the brazed joint, the stress theory of variable cross-section beam and the finite element simulation model of single grain brazed joint were established, and the grinding experiment of single diamond abrasive grain was carried out. The results indicated that the grinding force of the truncated octahedron grain exceeded that of the pyramid grain, the normal grinding force ratio of the truncated octahedron grain to the pyramid grain was about 1.49~3.38, while the tangential grinding force ratio was 1.67~2.77. The normal stress and shear stress of the brazed joint decreased with the grain size increasing, the smaller grains generated large stress subjected to the concentration of grinding force and bore greater failure risk at the brazing joint. The magnitude and position of the stress peak directly led to the difference in the abrasive wear form of the pyramid grain and the truncated octahedron grain. The main wear form of the pyramid grain was characterized by the rapid broken and flattened of the sharp angle and then the wear platform appeared, while the wear form of the truncated octahedron with micro-fracture, then the wear platform appeared and moved to the flank face. The wear forms in the simulation were well consistent with the experiments, which could potentially be applied to the grinding wheel design.