Dynamic Stresses in Granular Assemblies with Microstructural Defects

Abstract

An experimental study was conducted to investigate the effects of microstructural defects, such as inclusions and voids, on the wave propagation phenomena in granular materials. The granular materials as well as the defects were simulated using circular disks in both one‐ and two‐dimensional experiments, The defects were of two types, namely, inclusions and voids. Dynamic photoelasticity and high‐speed photography were used to study the effects of these defects on the local stressfield as the stress wave passed by. The dynamic loading was achieved by detonating a small amount of an explosive on top of the model assembly. The experimental results indicate that both inclusions and voids produce local wave scattering through various reflection mechanisms. Inclusions increase the wavelength of the loading pulse and produce more local attenuation and voids can change the local energy‐transfer paths.