Three-dimensional tractive rolling contact analysis of functionally graded coating-substrate systems with interfacial imperfection and frictional anisotropy

The three-dimensional tractive rolling contact analysis of functionally graded coating-substrate systems is conducted. The surface frictional anisotropy is described by Coulomb's orthotropic friction law, and the discontinuous transmissions of stress and displacement at the coating-substrate interface are formulated by a coupled dislocation-like and force-like interfacial imperfection. A multi-layered model is used to simulate the coating with arbitrarily varying thermo-elastic properties, and the conjugate gradient method and discrete convolution-fast Fourier transform algorithm are employed to obtain the spatial thermo-elastic responses of tractive rolling contact. The calculated results show that the maximum traction increases and the slip zone shrinks with increasing the ratio of lateral friction coefficient to the longitudinal friction coefficient, and the interfacial imperfection can cause a distinct jump of equivalent stress. Additionally, due to the slight frictional heat effect, the influences of inhomogeneous thermal parameters on contact pressure are much lower than those of shear modulus.