Failure-mechanism models for excessive elastic deformation

Design situations where excessive elastic deformations can compromise system performance, thereby acting as a failure mechanism, are illustrated. Models, based on continuum mechanics, to design against such failures are presented. Two examples illustrate the use of these models in practical design situations in electronic packaging and in mechanical systems. The examples use deterministic models, for simplicity of presentation. In reality, each of the variables in the design equation is uncertain, e.g. geometric dimensions, material properties, and applied loads. If these uncertainties are important then they must be accounted for by the usual statistical methods.>