ABSTRACT
Elastic deformation of a transversely isotropic half-space with a coating is considered. The coating consists of two layers: the upper one is homogeneous while the lower one is functionally graded. Elastic moduli of the functionally graded interlayer are described by arbitrary independently varying differentiable positive functions of depth coordinate. Torsion of the half-space by a circular punch is studied. Integral transformation technique is used to reduce the contact problem to solution of an integral equation. The kernel transform of the integral equation is constructed numerically. The bilateral asymptotic method is used to construct approximated analytical solution of the problem. The solution is asymptotically exact for small and large values of relative coating thickness and is of high accuracy for intermediate values. Calculation of the elastic displacements, stresses and strains inside the half-space is discussed.
