Aims

On completion of this tutorial you should:

• Appreciate the meaning of a misfit strain between the stress-free (in-plane) dimensions of two layers
• Understand how misfit strains can arise and how they give rise to stresses and strains in the layers, depending on their elastic properties and thicknesses
• See how the general case is simplified when one of the layers (a coating) is much thinner than the other (a substrate) and understand the Stoney equation
• Be able to predict the curvature that tends to arise in such systems
• Be able to predict whether debonding is likely to occur, given the value of the interfacial fracture energy