S. Mohammadi, A. Bebamzadeh,
Volume 4, Issue 4 (12-2006)
Abstract
Explosion has always been regarded as one of the most complicated engineering
problems. As a result, many engineers have preferred rather simplified empirical approaches in
comparison to extremely complex deterministic analyses. In this paper, however, a numerical
simulation based on the combined finite/discrete element methodology is presented for analyzing the
dynamic behavior of fracturing rock masses in blasting. A finite element discretization of discrete
elements allows for complex shapes of fully deformable discrete elements with geometric and
material nonlinearities to be considered. Only a Rankine strain softening plasticity model is
employed, which is suitable for rock and other brittle materials. Creation of new lines/edges/bodies
from fracturing and fragmentation of original objects is systematically considered in the proposed
gas-solid interaction flow model. An equation of state is adopted to inexpensively calculate the
pressure of the detonation gas in closed form. The model employed for the flow of detonation gas
has resulted in a logical algorithmic procedure for the evaluation of spatial distribution of the
pressure of detonation gas, work done by the expanding gas and the total mass of the detonation gas
as functions of time indicating the ability of model to respond to changes in both the mass of
explosive charge and the size of the solid block undergoing fracture. Rock blasting and demolition
problems are amongst the engineering applications that are expected to benefit directly from the
present development. The results of this study may also be used to provide some numerical based
reliable solutions for the complex analysis of structures subjected to explosive loadings.