Papers by Author: Li Xing Xiao

Abstract: Dynamic impact experiments of man-made rock were carried out with the Split Hopkinson Pressure Bar (SHPB) apparatus in this paper. The impact process was analyzed and the influence of rock porosity on dynamic mechanical behavior was investigated. The stress-strain curves in rock were obtained by the one-dimensional stress wave theory. The curve lays foundation for numeric simulation of rock fracture under impact loading. The damage profiles of rock specimen under the impact loading show that the man-made rock exhibits obvious shear damage under the impact loading because it is a typical porous medium containing large quantities of defects such as pores, cracks and grain boundaries at the microscale. The experimental results also indicated that rock porosity plays an important role in dynamic mechanical behavior.

Abstract: The armed steel target impacted vertically by tungsten spheres with different initial velocities and masses was studied by experiments. The macroscopic properties of crater were analyzed by the shape features of crater, the size dimension of crater, cracks along the penetration tunnel and the characteristics of recovered tungsten spheres. The results show that the everted rimmed and irregular shape of crater is heavier with velocity and mass of tungsten sphere. The shape of the top surface of impactor changes from the original sphere to the flat profile and the mass shows an obvious drop at a higher impact velocity The ratio of the crater diameter to the diameter of tungsten sphere, and the ratio of the crater depth to the crater diameter both descend with the mass at the same initial velocity of tungsten sphere. The specific expression of nondimensional penetration depth versus dynamic pressure is given by experiment data.