Characterization of dynamic mechanics and damage energy dissipation of simulated lunar soil splitting and stretching under impacts

Abstract: To investigate how different shock loads affect the simulated lunar soil's dynamic response, surface energy dissipation law, and damage mode of simulated lunar soil under different impact air pressures were analyzed by using the visualized Split Hopkinson Pressure Bar (SHPB) test system, and the dynamic splitting mechanism of simulated lunar soil and the The influence factors of dynamic tensile strength were investigated. The results show that: under the impact load, the stress-strain curve of the simulated lunar soil can be divided into four stages based on the energy dissipation law, and the crushing dissipation energy and crushing dissipation density show an exponential growth trend with the increase of the impact load; the damage dissipation energy of the simulated lunar soil during the impact process directly reflects the degree of microfracture development in the specimen, and with the increase of the impact pressure, the damage dissipation energy of the simulated lunar soil increases, and the damage dissipation energy reaches the maximum value when the specimen undergoes cleavage damage, and the damage dissipation energy of the simulated lunar soil under the impact pressure reaches the maximum value, The damage dissipation energy reaches the maximum value when the specimen splits; under different impact air pressures, the simulated lunar soil specimens show the damage pattern of center cracking, and the specimen is damaged into two relatively intact parts; the dynamic tensile strength increases linearly with the increase of impact air pressure, and shows a logarithmic growth trend with the increase of the energy-dissipating density.