On the receding contact between an inhomogeneously coated elastic layer and a homogeneous half-plane

Abstract The general double contact problem of an inhomogeneously coated elastic layer indented against a homogeneous half-plane by a rigid punch is investigated. The problem is solved under the assumptions that the contact at both interfaces is frictionless, the three materials possess different shear modulus, and the shear modulus of the functionally graded coating varies exponentially. By the standard method of Fourier integral transforms, the problem is reduced to a system of singular integral equations, which are subsequently transformed into algebraic ones by Gauss–Chebyshev integration formulas. Massive numerical experiments are performed to quantify the influence of stiffness distribution in coating, material and geometric properties of the compound structure, and indentation load on the contact pressure and contact length at both surfaces of contact. The results suggest that in the case of a hard and thick coating large pressure reduction can be achieved for the receding contact at the layer/substrate interface.