Expressions relating curvature and mismatch strain for arbitrary coating thicknesses and for large deflections are compiled and discussed. A robust fitting method based on the mean absolute deviation is used. Experiments are performed on a TiN coating. Edge effects and influence of compressive residual stress on the cracking of a diamond coating are discussed. The stress concentration at a curved residually stressed interface is studied by finite element analysis.
Interfaces are generally non-planar at some length scale.
Smooth non-planar interfaces in elastic bimaterials under residual stress are analysed by finite element calculations. The effect of different interface profiles, ratio of layer thickness to interface roughness, and elastic mismatch is investigated. Generally, interface stresses of a magnitude comparable with the residual stress level in a layer with plane interface are induced. The initial stages of growth of an interface crack is studied, and the crack is shown to be arrested when reaching a neighbouring inflexion point of the interface profile.