Fracture loads of sharp and blunt asperities under normal and tangential loading

Fracture of interlocking asperities due to normal and shear surface traction affects wear of the brittle materials and durability of the structural components. Upon reaching a critical force, a crack initiates from the asperity notch tip, propagates, and either stops after the energy release rate decreases down to its critical value or leads to complete fracture of the structure. Fracture force was predicted using an analytical model as a function of the asperity shape (width, height, opening angle, and root radius), applied force inclination angle, and friction coefficient. A very good agreement was found between theoretical and numerical results in terms of fracture force for all the studied cases for the blunt and sharp asperity bases.