PARDEX: a program for computing the environmental risk associated with accidental explosions

The environmental risk associated with damage caused by fragments generated by accidental explosions can be defined as the probability that a fragment will hit an object of a given size and a given location. This probability can be calculated under the assumption that the initial velocity and launching angle of a fragment are uniformly distributed random variables. Since air drag cannot be neglected in most practical cases, equations of motion must be solved numerically to compute this probability. This paper presents two implementations of a procedure for calculating this probability: an exact method which requires that the equations of motion be solved whenever information about the range of a fragment must be computed, and an approximate method in which the data for range and velocity is tabulated and interpolated.