IR DIAGNOSTICS FOR DYNAMIC FAILURE OF MATERIALS

摘要

This project explores the thermodynamics of dynamic deformation and failure of materials using high-speed spatially-resolved infrared (IR) measurements of temperature. During deformation mechanical work is converted to different forms of energy depending on the deformation processes. For example, it can be dissipated as heat in purely plastic deformation, stored as strain energy in dislocations in metals and in oriented polymeric molecular structures, and expended during the generation of new surfaces during damage and fracture. The problem of how this work is converted into these various forms is not well understood. In fact, there exists a controversy for the relatively simple case regarding the amount of work dissipated as heat during uniform plastic deformation. The goals of this work are to develop dynamic IR temperature measurement techniques and then apply them to gain a better understanding of the dynamic failure processes in both metals and polymeric composite materials. The experimental results will be compared against predictions of existing constitutive models and guide the development of higher fidelity models if needed.