Explosive Fragmentation

Abstract

The ability to predict fragmentation of geological materials due to explosive loading has increased significantly over the past two decades. There are currently a number of hydrodynamic finite difference Lagrangian codes available which do a reasonable job of predicting the fracture and fragmentation that results from explosive loading [1–3]. These codes are particularly useful for estimating the amount of damage that has occurred at a particular time after the explosive has detonated and the resulting shock waves have passed over the material being fragmented. These codes are not of value for later times in the event during which the fragmented material is thrown away from the vicinity of the borehole. There are, however, a number of other codes which use discrete elements that are useful for predicting the final location of the fragmented materials [4–6]. These discrete element codes normally use the fragmentation pattern that results from the stress wave action as the beginning stage for determining the discretation used to predict later particle motion. These elements are normally subjected to a pressure loading which is determined from estimates of the gas generated during the detonation of the explosive.