Explosive attacks are increasing day by day in the present era, and the design optimization of protective structures without increasing their weight is mainly a critical task for vehicles. Assessment of the dynamic response of the structures under explosive loading through experimentation is costly, with many restrictions, and highly harmful for both people and the environment. Hence, the present study deals with an explicit numerical investigation of the protective sandwich structures’ blast performance. The influence of the number of stages of honeycomb on the sandwich structures’ blast mitigation capacity was evaluated with the effective utilization of face sheets’ material as their intermediate sheets while maintaining the total volumes as well as masses of the structure's constant. The explosive loads of 1 to 3 kg of trinitrotoluene were used for the stand-off distance of 100 mm. The rate-dependent Johnson-Cook plasticity model was implemented on the designed sandwich models to discover their damage behaviors. The sandwiches’ face deflection, energy absorption, kinetic energy variation, and crushing behaviors were considered to characterize their blast mitigation capacity. The obtained results showed that increasing the number of stages of core in the sandwich structure by using a fraction of the back face sheet materials for intermediate sheets significantly improved their blast performance without increasing their volume occupancies and masses. For the two-stage and three-stage sandwich designs, 50% and 20%, respectively, utilization of their back face material for their intermediate sheet was found to be optimal.

中文翻译：

---

易受爆炸载荷影响的多级夹层结构的动态响应优化

当今时代，爆炸袭击日益增多，在不增加其重量的情况下优化防护结构的设计主要是车辆的一项关键任务。通过实验来评估结构在爆炸载荷下的动态响应成本高昂，受到许多限制，并且对人类和环境都非常有害。因此，本研究对防护夹层结构的爆炸性能进行了明确的数值研究。在保持结构总体积和质量恒定的情况下，有效利用面板材料作为中间板，评估蜂窝层数对夹层结构减震能力的影响。对于 100 毫米的间隔距离，使用 1 至 3 千克三硝基甲苯的爆炸载荷。在设计的三明治模型上实施依赖于速率的 Johnson-Cook 塑性模型，以发现其损伤行为。三明治结构的面偏转、能量吸收、动能变化和破碎行为被认为是表征其爆炸缓解能力的特征。获得的结果表明，通过使用一小部分背面板材料作为中间板来增加夹层结构中核心的级数，可以显着提高其爆炸性能，而无需增加其体积占用率和质量。对于两级和三级夹层设计，中间片材背面材料的利用率分别为 50% 和 20%，被发现是最佳的。