Air Blast Loading of Cellular Media

Abstract

Much of the early literature on shock and wave propagation in porous media is found in the geophysical literature, but Riemann [1] was the first to describe how a compressional wave transforms into a shock wave. A century later, shock and particle velocity measurements in solids enabled McQueen et al. [2] to develop Hugoniots for minerals thought to comprise the earth’s interior. This naturally led to the study of shock-induced phase transformations in minerals as the possible cause of the major body-wave velocity discontinuities in the Earth. The interest in shock wave loading of porous geologic media accelerated with the advent of underground nuclear testing (e.g. at the Nevada test site [3]), and concurrent computational modeling of such events [4]. Studies of shock and wave propagation in porous and permeable sedimentary media [5] ensued during the era of oil exploration. Today, the wide-spread use of porous materials such as cellular foams and honeycombs in structural applications is attributed to their capacity to absorb energy, particularly at low impact velocities. Surprisingly, however, the use of porous crushable materials subjected to air blast pressure loading has, in many instances, led to the enhancement rather than mitigation of blast effects [6, 7, 8].