Thin layer with circular debonding over a substrate under either axisymmetric compression or thermal loading.

Abstract

The objective of this dissertation is to present analytical solutions to the problem of a circular debonded thin film on a substrate subjected to either axisymmetric compressive stress or uniform thermal loading. In the case of the axisymmetric compressive stress, the solution method utilizes the three-dimensional equations of elastic stability while allowing the debonded region to be slightly open. The in-plane axisymmetric compressive stress is present only in the thin film. In the case of thermal loading, both the film and the substrate are subjected to the same uniform temperature variation. The solutions to both cases are obtained by using mathematical techniques appropriate to mixed boundary value problems in the theory of elasticity where the governing equations are obtained as a system of singular integral equations. These equations are then reduced to a system of algebraic equations leading to the determination of the stress intensity factors and the corresponding phase angles.