Large internal stresses in particle-reinforced composites subjected to dynamic loads

Discontinuously reinforced particulate composites are often used in applica tions where they may be subject to dynamic mechanical loads. A rational ana lysis of composites under these loadings to predict the initiation of failu re and its subsequent accumulation must concentrate on the stress state at the microstructured level. In this study, the steady-state stresses resulti ng from a dynamic loading in a particle-reinforced metal-matrix composite a re determined, and the stress concentration factors at the interface betwee n the particle and matrix are obtained in an effort to determine the parame ters which govern the dynamic response. It is found that the dynamic stress concentrations are dependent on the frequency of excitation and elastic pr operties of the composite, and they can be larger than those encountered un der static loading. (C) 1999 Elsevier Science Ltd. All rights reserved.