水下爆炸冲击下码头结构动力响应的数值模拟

为探究水下爆炸冲击对码头结构的结构损伤,开展爆炸荷载下高桩码头结构的数值模拟分析。基于ALE多物质流固耦合法,建立了码头结构的水下爆炸Lagrange-Euler全耦合模型,基于Cole经验公式,验证了模拟的可靠性,研究了起爆距离、起爆深度以及TNT当量对码头结构动力响应特性的影响规律。结果表明,在水下爆炸冲击荷载作用下,所有桩柱产生不同程度损伤,码头端部的第一根桩柱底部基岩区域以及与横梁相连的基岩区域塑形损伤破坏较为严重;当TNT炸药的起爆距离较小时,桩柱上的反射波要强于水底面的反射波,并会与之相抵消,作用在桩柱上的反射稀疏波会随之削弱;在其他条件相同的情况下,当起爆点到自由水面的距离与起爆点至基础底面距离之差的绝对值越大时,爆炸荷载作用于码头结构上的压力峰值会显著增大。

Numerical simulation of dynamic response of wharf structures under underwater explosion impact

In order to explore the structural damage of wharf under underwater explosion impact, the numerical simulation analysis of piled wharf under explosion load was carried out. Based on the ALE multi-material fluid-solid coupling method, the Lagrange-Euler fully coupled model of wharf in underwater explosion was established. Based on the Cole empirical formula, the reliability of the simulation was verified, and the effects of detonation distance, detonation depth and TNT equivalent on dynamic response characteristics of wharf were studied. The results show that under the impact load of underwater explosion, all piles have different degrees of damage, and the plastic damage of the bedrock areas at the bottom of the first pile at the wharf end and connecting with the beam are rather serious. When the detonation distance of TNT is small, the reflected waves on the pile are stronger than those on the bottom and will offset against them, and the reflected sparse waves on the pile will weaken accordingly. Under the same other conditions, with the larger absolute value of the distance difference from the initiation point to the free water surface and the distance from the initiation point to the foundation bottom, the peak value of the pressure exerted by the explosion load on the wharf will increase significantly.