FAILURE MECHANISM MODELS FOR DUCTILE FRACTURE

This tutorial illustrates design situations where ductile fracture of some components can compromise system performance, thereby acting as an overstress failure mechanism. Analytic (physics-of-failure) methods, based on continuum fracture-mechanics principles, are presented to design against such failures. Examples illustrate the use of these models in practical design situations in mechanical engineering and electronic packaging. The design equations are based on continuum mechanics rather than on molecular micro-mechanics, and can be implemented in an engineering design environment. The associated stress-analysis often requires numerical finite-element techniques. The methods for material-property characterizations have matured appreciably over the past 40 years and are specified in engineering handbooks.