Abstract: Composite materials are widely used in the field of ballistic and explosion prevention due to their excellent overall toughness and impact resistance, and the internal stress wave propagation of composite materials is very important to their impact resistance. The finite element software is used to study the effect of different interface structures and structural parameters on the stress wave propagation of the impact material composed of two layers of composite materials under the impact load generated by explosion. The results show that the impact load generated by explosion continues to propagate in the form of stress wave when reaching the composite material. When arriving at the interface, the stress wave will be reflected and transmitted due to different wave impedances of materials on both sides. Compared with the flat interface, the triangle interface has stronger attenuation effect on the stress wave. With the decrease of the angle of triangular interface, the peak value of stress wave reaching the second layer of composite decreases gradually. Under the same angle, the peak value of stress wave decreases first and then increases with the increase of interface thickness. This research is important in the field of ballistic and explosion protection.

Key words: composite material, stress wave propagation, interface geometry, blast-induced shock waves, oblique incidence