爆炸冲击下水下防护门结构动态响应及抗力参数分析

Dynamic Response and Resistance Parameter Analysis of Underwater Blast-Resistant Door Structures under Explosive Shocks

摘要:

近年来水下公共设施遭受到水下突发爆炸冲击的风险日益增加，且爆炸一般发生在工程口部位置。水下防护门是工程口部抵抗爆炸冲击荷载、保障水下工程安全的重要防护设施。为研究水下爆炸冲击作用下钢制平板式防护门的结构动态响应及破坏模式，通过有限元软件建立了基于ALE算法的水下爆炸背空板的全耦合数值模型， 得到的冲击波荷载与经验值对比，验证了数值计算的精度；采用直接加载的方法与耦合模型结果进行对比，验证了直接加载方法的有效性；为进一步探讨水下爆炸对钢制平板式防护门结构的毁伤特性，建立了防护门在水下爆炸冲击荷载下的三维数值模型，分析了炸药当量、起爆距离、静水压力、迎爆面与背爆面厚度、四周支撑面板厚度等因素对防护门抗爆性能的影响规律。结果表明：随着炸药当量的增大及起爆距离的缩短，防护门峰值位移逐渐增大， 结构主要以局部骨架梁屈曲变形与整体弯曲破坏伴随着骨架梁压曲失稳两种破坏模式；在相同的爆炸工况下，增大迎爆面、背爆面及四周支撑面板的厚度可使防护门具有更强的抗爆性能，在实际工程设计中可在一定程度上增加面板厚度。

Abstract:

In recent years, the risk of underwater public facilities being impacted by sudden explosive shocks has been increasing, with explosions typically occurring at the project entrances. Underwater blast-resistant doors are crucial protective structures at the project entrances, designed to resist explosive shock loads and ensure the safety of underwater projects. This study aims to investigate the dynamic response and failure modes of steel plate blast-resistant door structures under underwater explosive shocks. Using finite element software, a fully coupled numerical model of underwater explosion with a backing plate was developed based on the Arbitrary Lagrangian-Eulerian (ALE) algorithm. The shockwave load obtained was compared with empirical values, validating the accuracy of the numeri-cal calculations. The results of the direct loading method were compared with those of the coupled model to verify the effectiveness of the direct loading method. To further explore the damage characteristics of the steel plate blast-resistant doors under underwater explosive shocks, a three-dimensional numerical model was developed. The study analyzed the effects of factors such as explosive equivalent, detonation distance, hydrostatic pressure, thickness of the explosion-facing and back-facing surfaces, and thickness of the surrounding support panels on the doors' blast resistance performance. The results showed that as the explosive equivalent increased and the detonation distance decreased, the peak displacement of the doors gradually increased. The structure primarily had two failure modes: local buckling deformation of the skeleton beams and overall bending failure accompanied by buckling instability of the skeleton beams. Under identical explosion conditions, increasing the thickness of the explosion-facing surface, back-facing surface, and surrounding support panels enhanced the blast resistance of the doors. In practical engineering design, panel thickness can be increased to improve blast resistant performance.