Experimental Investigation of Obliquely Incident Blast Wave Effect on Deflection of Running Cracks

Abstract

Abstract Dynamic caustics in conjunction with high-speed photography were used in experiments to investigate the interaction of obliquely incident blast stress waves with running cracks. The dynamic photoelastic experiment method was used to supplement and improve the effects of different blast stress wave properties on the running crack. This indicated that the crack-tip mode II stress field affected the crack deflection direction. When the moving crack-tip mode II stress intensity factor KII was positive, the crack deflected clockwise. When the stress intensity factor KII was negative, the crack deflected in the counterclockwise direction. The incident direction of the blast stress wave affected the deflection of the crack. When the direction of the blast stress wave was the same as the direction of the moving crack propagation, the moving crack deflected away from the blast wave source. When the blast stress wave propagation direction was opposite to the crack propagation direction, the crack deflected toward the blast wave source. During the interaction of an obliquely incident blast stress wave with a moving crack, the P wave caused the deflection of the crack. The tails of the P wave and S wave interacted with the kinked crack to increase the mode I stress intensity factor KI and the crack propagation velocity.