水下近场爆炸双层防护结构抗爆能力的数值模拟分析

摘要

同步考虑水下近场爆炸冲击波载荷与气泡射流载荷的作用，综合分析双层防护结构型式及尺度对其抗爆能力的影响，可为双层防护结构的抗爆设计提供直接技术支持。采用基于欧拉法的气泡动力学程序模拟气泡的近壁脉动过程，基于能量等效原则，将射流水柱对结构的冲击简化为等效的射流载荷，通过编制MSC.Dytran软件子程序，在冲击波数值模拟阶段后自动添加等效射流载荷，实现更接近实际情况的双层防护结构遭受水下近场爆炸过程的数值模拟。以内壳单位板厚变形能表征双层防护结构的抗爆能力强弱，通过改变结构型式与尺寸参数，对不同支撑结构板厚、内壳板厚和内外壳间距下结构的抗爆能力进行批量计算，以结构总重和抗爆能力为双重目标，借鉴多目标优化思想，得到双层结构抗爆能力的最优解集。计算结果表明：当内外壳厚度及其间距一定时，存在最佳支撑结构板厚；在同等结构重量情况下，Y型双层结构能提供更强的抗爆能力。%This paper provides direct technical support to the explosion-resistance design by considering both the shock wave and jet load simultaneously and taking into account of the effect of double shell struc⁃ture types and sizes during the underwater near-field explosion. Based on the bubble pulsation analysis us⁃ing Eulerian method in the vicinity of a rigid wall and the principle of energy equivalence, the dynamic re⁃sponse of a double shell structure subjected to underwater near-field explosion is numerically simulated. The jet load is then simplified and applied after the shock wave by using the Msc.Dytran software subrou⁃tine. Models with different structural types and sizes are also calculated and an optimal solution set which targets both the weight of the structure and the explosion-resistance capability is obtained via the multi-ob⁃jective optimization approach. The results show that the optimum thickness of the support structure can be determined when the thickness of outer and inner shells and the distance between them are constant. Mean⁃while, Y-frame double shell structures tend to provide higher explosion-resistance capability when the weight of structure is constant.