Explosion power evaluation based on the energy absorption characteristics of expansion tube structure

Abstract

With the rapid advancement of the new generation of ammunition, the evaluation of the explosion power has received worldwide attention. To assess the power of blast waves generated by explosives, an explosion power evaluation method, based on analyzing the energy absorption characteristics of an expansion tube structure (ETS), is proposed in this paper. Explosion experiments and numerical simulations are carried out to investigate the energy absorption characteristics of the ETS under blast loading, and a verified theoretical model is developed to predict the energy absorption per unit area (EAUA) of the ETS. The parametric studies demonstrate a quadratic positive correlation between the EAUA of ETS and the explosive mass/(standoff distance)2, as well as a linear correlation with the reciprocal of areal density of the ETS. However, the effect of equivalent strength of the ETS on the EAUA is less significant. Furthermore, an explosion power model is established using dimensional analysis. The evaluation errors of this model in estimating explosive mass are -11.34 % to 14.67 % when compared with the actual mass of the explosive trinitrotoluene (TNT), and it also shows errors of -13.94 % to 0.97 % when compared with the explosive mass estimated through free field overpressure sensors, which all fall within the range of ±15 %, demonstrating that the proposed method meets the accuracy requirements for explosion power evaluation. This research provides a novel and accurate methodology for evaluating the power of ammunition in explosion field, especially for testing in extreme conditions.