NUMERICAL SIMULATION AND EXPERIMENTAL RESEARCH ON THE DAMAGE EFFECT OF HIGH-STRENGTH CONCRETE UNDER EXPLOSION LOAD

The damage effect of high-strength concrete target plate under the action of explosion load is very complicated. The corresponding experiment is designed for the damage problem of high-strength concrete target plate under the action of explosion load, and the experimental results are verified and analyzed by using the virtual fluid Euler-Lagrange bidirectional fluid-structure coupling algorithm (GEL) constructed by the author. The effects of different charge modes, charge amount, strength of concrete target plate and explosion height on the damage results are discussed in detail. The difference of action mechanism between external and implosive loads is summarized, and the damage mechanism of high-strength concrete under the action of explosion loads is revealed. The results showed that for the external explosion condition, the depth of the explosion pit under three different strengths of 600 g charge increased by 11.85%, 8.82%, and 7.71% compared to 300 g charge, while the diameter of the explosion pit increased by 15.71%, 8.51%, and 7.51%, respectively. This indicates that with the increase of concrete strength, the increase in the depth and diameter of the explosion pit with the increase of charge gradually decreases, and for concrete target plates of various strengths, the increase in the diameter of the explosion pit with the increase of charge is greater than the increase in the depth of the explosion pit. When the explosion height is 0, 5, and 10 cm respectively, the peak pressure of the explosion shock wave propagating to the center position of the concrete target plate is 16.08, 1.33 and 0.30 GPa, indicating that as the explosion height increases, the depth and diameter of the concrete target plate's explosion pit decrease. The closer to the concrete target plate, the smaller the decrease in the depth and diameter of the explosion pit. The shock wave decays exponentially with the increase of propagation distance, which is also the main reason for the differences in funnel pit damage under different explosion height conditions. For implosion loads, after the explosive detonates, the huge energy of the explosion shock wave cannot be dissipated into the air in a timely manner, which severely hinders the propagation of the shock wave and leads to a rapid increase in the pressure and density of the air inside the concrete wall. Taking the C120 high-strength concrete target plate as an example, the simulated depth and diameter of the explosion funnel pit of the concrete target plate under the action of 60 g explosive increased by 13.38% and 77.73% respectively compared to 30 g explosive, indicating that increasing the charge has a significant impact on the lateral damage of the target plate. Taking the 30 g explosive detonation condition as an example, the depth of the explosion pit of C120 high-strength concrete is reduced by 13.14% compared to C40 ordinary concrete, and the depth of the explosion pit of C160 high-strength concrete is reduced by 2.20% compared to C120 high-strength concrete. The reduction in the diameter of the explosion pit is 54.43% and 21.77%, respectively, indicating that high-strength concrete has stronger blast resistance than ordinary concrete. The lateral failure mode of concrete target plate under internal explosion is more obvious, which is slightly different from the failure mode under external explosion conditions. © 2024 Chinese Society of Theoretical and Applied Mechanics. All rights reserved.