Influence of Ground Impedance on Explosive Shock Wave Test Accuracy

Abstract

Different propagation media have different effects on explosion shock wave attenuation during the propagation process. Studying the attenuation effect of dielectric impedance on shock wave pressure is of great significance to accurately measure shock wave pressure and evaluate the ammunition damage power. This study analyzes the measured shock wave overpressure peak data of TNT bare charge (60 kg) on soil, sand soil, and concrete grounds. Dimensional analysis was used to establish the medium impedance expressed by material densityρ, burst center distancer, equivalent TNT quality ω, and impedance coefficient η. Based on this, the mapping relationship between the propagation medium impedance coefficientηand the shock wave overpressure peak value was established. The test data were analyzed, and the results showed that in the same explosive environment, different ground propagation media had different impedance effects on the shock wave pressure, which is specifically expressed as ηsoil>ηsandsoil>ηconcrete; the modified calculation model of shock wave pressure established using material impedance coefficient has a fitting accuracy of 93.39% to the measured data, which can well represent the attenuation law between different ground propagation media and shock wave overpressure peak. This provides a theoretical basis and method for obtaining shock wave pressure data in explosion field and verifying validity of the test data.