Study on visual propagation of explosion stress wave in gradient medium

Laminated composite rock body widely exists in engineering fields such as mining, tunneling, transportation construction and slope management, which is a common geological structure in nature. In this paper, we simulate layered composite rock body by epoxy resin material, and use dynamic photoelasticity-digital image correlation comprehensive experimental system to visualize and refine the propagation process of explosive stress wave in gradient medium, and study the attenuation law and energy flow density evolution law of explosive stress wave in two cases of forward gradient and reverse gradient. The results show that there is no obvious change in the number of stripe levels in the forward propagation path, and there is obvious reflection at the nodal surface, and the number of stripe levels in the reverse propagation path is in the attenuation pattern, and the kinetic-optical elasticity stripe at the nodal surface has a very good continuity, and the explosive stress wave has a better penetrability in the reverse-gradient medium. The change of joints and materials in the gradient medium changes the rate of horizontal stress attenuation, and the horizontal stress attenuation is faster in the forward gradient medium. Through the introduction of the Poincar´e vector to compare the energy flow density, it is found that in the same measurement point in the forward gradient materials in the energy flow density amount of the faster decay rate, the explosion stress wave propagation process in the forward gradient materials belongs to the “energy absorption” process.