Test and analysis of blast wave in mortar test block

Abstract

A strain gauge system poured in a mortar test block was used to study the propagation of blast waves generated by explosive charges. The shock waves were recorded with a super dynamic strain test system using strain gauges. The measured wave-forms were analyzed. The results show that the propagation of the blast wave in the experiment is mainly manifested by the joint action of the shock wave and the reflected tensile wave, and the action time is about 6 μs and 15 μs, respectively. At the same measuring point, the peak value of strain wave reaches 104 με, and the peak strain rate reaches 106 s−1. The attenuation of radial strain wave is faster than that of tangential strain wave, while the attenuation of gas is not obvious, and the compression strain on rock is greater than the tensile strain. Within the scope of the study, the loading of the blast wave is greater than that of the unloading. In the radial direction, with the increase of distance, the loading and unloading of shock wave on rock all showed a declining trend. The loading effect of the reflected tensile wave did not decay, and the unloading effect attenuated weakly. In the tangential direction, the loading effect of the shock wave on the rock first decreases and then increases, and the unloading damage of rock increases slightly. The loading effect of the reflected tensile wave on the rock first decreases and then increases, while the unloading damage nearly unchanged.