Study On Dynamic Behavior Of Impacted Porous Porous Rock

The mesoscopic characteristics have a significant influence on the macroscopic dynamic behavior of rock materials, which finally affect the cratering behavior impacted by Hypervelocity fragment. In this paper, a research is focusd on the the shock compression behaviour of rock materials with different mesoscopic characteristics, such as porosity and water, by conducting theoretical analysis, numerical and experimental research. Based on the hypervelocity impact experiments, the impact cratering morphology and characteristics of dry and wet rock materials are studied. The main contents are summarized as follow:(1) Theoretical model of equation of state(EOS) of rock material with porosity and water.Based on the impact dynamics theory, a theoretical analysis on the equation of state of rock material under impact loading has been presented to investigate the shock compression behaviour of rock materials with different meso-structure, such as porosity, and water. Theoretical results of different water content and porosity of rock materials have been calculated by using above model. The calculated results from theoretical model are agree well with corresponding experiment results.(2) Msoscopic numerical simulations of porous and wet rock materials.An mesoscopic simulation model, based on the electron micrograph of meso-structure of typical rock materials, has been established. Numerical studies on the compressive processes of rock materials have been conducted in mesoscopic by using AUTODYN software. The results show that the microscopic finite element numerical model, which describes the impact of the rock material compression characteristics, can reflect the dynamic behavior of the rock material for particles, porosity and water.(3) Shock compression experiment studes on porous and wet rock material.Based on hypervelocity flyer acceleration platform, experimental studies on the shock compression of rock materials have been performed. Comparative analysis of shock propagation of the dry and wet rocks has been presented. The parameters of shock wave in rock material were obtained, by using the PVDF thin film piezoelectric transducer, then compared with theoretical and simulation results.(4) Hypervelocity impact cratering studes on porous and wet rock material.The study focuses on impact crater morphology experiments in dry and wet rock. The Hugoniot parameters with different meso-structure of rock materials have been determined and applied in impact cratering process simulations. It indicates that the rock material may well reflect the macroscopic mechanical response by microscopic characteristics.