Study of the coupling characteristics of damage elements with cased charge

Abstract

In this paper, the coupling characteristics of fragments, detonation products and explosive shock wave have been studied. Although a large number of studies have been conducted to discuss the damage effects of structures under the combined loading of blast and fragments impact, there is a lack of research on the coupling characteristics of damage elements and their mechanism of action. This study uses the law of conservation of energy to propose a more reasonable method to evaluate the velocity of fragment. In addition, the isentropic expansion theory of bare charge detonation products is used to explore the expansion characteristics of cased charge detonation products, and the expansion process of cased charge detonation products can be divided into three phases. The results show that the limiting expansion volume of detonation products with cased charge is smaller than that of bare charge due to the inhibiting effect of the casing. Taking into account the energy absorbed in the crushing of the casing, the shock wave produced by the explosion of the cased charge is equal to the shock wave produced by the explosion of a given amount of bare charge, and the corresponding formula is given. Then, based on the known performance parameters of each damage element, the arrival time of the damage element at the target structure is systematically analyzed, and the coupling of the damage element is divided into five phases according to the arrival time, and the range of damage effect of each coupling phase is analyzed in two cases. Finally, a numerical simulation based on Euler's method is performed, and the theoretical results agree well with the numerical simulation results.