金属蜂窝夹层结构抗水下爆炸特性

金属蜂窝夹层结构是一种新型的舰船防护结构，在舰船防护领域具有广阔的应用前景，但目前缺乏对其在实际水下爆炸载荷作用下动态响应的研究。为研究金属蜂窝夹层结构在水下爆炸载荷作用下的动态响应及防护性能，设计并制备了背板加筋蜂窝夹层结构样件以及相应的浮箱，在大型露天水池中进行了水下实爆 实验；通过声固耦合算法对结构响应进行模拟，实验结果与模拟结果吻合良好，随后分析了蜂窝夹层板的变形过程及能量吸收特性，量化了载荷参数（冲击因子）及结构参数（前后面板厚度比和芯体相对密度）对结构动态响应的影响；最后，以蜂窝夹层板的面密度和后面板中心点最大变形的无量纲量为目标函数，使用NSGA-Ⅱ遗传算法对结构进行了多目标优化，得到对应的Pareto前沿。结果表明，随着冲击因子的增大，蜂窝夹层板整体变形显著增大，蜂窝芯体始终是主要的吸能构件，但其吸能占比逐渐降低；随着前后面板厚度比或芯体相对密度的增加，蜂窝夹层结构的最大变形呈现先降低后升高的趋势，同时呈现不同的变形模式，芯体相对密度对结构变形的影响更为显著；对蜂窝夹层结构开展多目标优化可有效降低结构的面密度及最大变形，优化结果可为蜂窝夹层结构的设计选型提供参考。

Resistance of all-metallic honeycomb sandwich structures to underwater explosion shock

All-metallic honeycomb sandwich structure is a new kind of ship protection structure, which has a broad application prospect in the field of ship protection. However, there is not enough research on the dynamic response of honeycomb sandwich structures under an actual underwater explosion load. The dynamic behavior and protective performance of honeycomb sandwich structures subjected to the underwater explosion load were investigated, both experimentally and numerically. A backplane stiffened honeycomb sandwich structure and the corresponding buoyant box were designed and fabricated for the subsequent experimental study in a large open water pool. The structural response was numerically simulated by using the coupled acoustic-structural approach (integrated in commercial FE code ABAQUS/Explicit). The numerical simulation results are in good agreement with the experimental measurements. Then, the deformation process and energy absorption characteristics of the honeycomb sandwich structure subjected to underwater explosion load were investigated. The effects of the load parameter (impact factor) and two geometric parameters (i.e., facesheet thickness ratio and core relative density) on the dynamic response of the sandwich structure were analyzed. Finally, the Pareto optimal designs with minimize value of non-dimensional areal density and minimize value of non-dimensional maximum deformation of the central point on back facesheet were obtained by using the NSGA-Ⅱ algorithm. The results show that with the increase of the impact factor, the overall deformation of the structure increases significantly. The honeycomb core is the main energy absorbing substructure during this process, and its energy absorption ratio gradually decreases. With the increase of either face sheet thickness ratio or core relative density, the deformation of the structure first decreases and then increases, accompanied by changes in deformation modes. The influence of core relative density is more significant. The optimized structures obtained from multi-objective optimal design effectively reduce the areal density and the maximum deformation, which can be used as a reference for the future design of honeycomb sandwich structures.