二维原子晶体增强异质复合装甲抗弹射损伤模型及计算

Large-area high-quality graphene and similar two-dimensional atomic crystals (2DAC) have been synthesized, and are being used in composite materials. Graphene-like 2DAC, with high longitudinal strength (rigidity in-plane), low lateral stiffness (flexibility out-of-plane) and low density, meet the requirements of ideal armor materials, and the mechanical properties under ballistic impact loading have drawn the attention of researchers. Here, we will construct the molecular models of 2DAC (e.g. graphene and hexagonal boron nitride) and laminated heterostructures reinforced by 2DAC, and focus on the dynamic mechanical responses of above models subjected to high-speed impacts. By improving miniaturized ballistic experiments, the physical and mechanical behaviors, e.g. impact energy dissipation/mixed-mode dynamic fracture, will be investigated during projectile penetration and perforation. Furthermore, we will examine the dynamic failure of laminated heterostructures under complex stresses; study the kinetic phenomena of intra-/inter-layer stress wave propagation, and evaluate the limiting penetration velocity V50 by modifying the penetration model. Finally, the kinetic energy dissipation efficiency of graphene-like crystal reinforced composite laminates of mixed-dimensional van der Waals heterostructures will be revealed by comparing with traditional armors, which is expected to guide the design of new super-tough, light weight armor laminates and provide the theoretical support for promoting the protection performance of weapons.

高品质石墨烯及其类似晶体结构材料已实现大规模制备，并逐渐应用在复合材料中。类石墨烯二维原子晶体具有极高的纵向强度(面内刚硬)、较弱的横向刚度(离面柔软)、密度小的特性，符合理想装甲材料的要求，其弹道冲击载荷作用下的力学性能引起研究者的关注。本项目拟构建弹射冲击下类石墨烯二维晶体及其异质复合层的微观分子模型，深入计算分析其受高速微弹丸冲击后的力学响应，并设计改进微型弹道试验，探讨弹丸侵彻、穿透异质复合层过程中能量耗散/破坏形式等物理力学行为，考察复杂应力作用下的动态损伤、断裂过程，研究层内/层间应力波扩散等动力学现象，改进侵彻力学模型，评估极限穿透速度，揭示类石墨烯晶体增强多维异质复合层抗冲击能力、动能耗散面密度，并与传统装甲材料对比，以期设计新型超强韧轻质装甲，为显著提高武器防护性能提理论依据。

类石墨烯原子晶体材料具有极高的纵向强度，较低的面外刚度和较小的密度，符合理想装甲选材要求，其弹道冲击载荷作用下的力学性能引起研究者的关注。本项目利用分子动力学模拟、分子结构力学计算，研究了二维晶体增强异质复合层受高速弹丸冲击后的力学响应。首先，以石墨烯、六角氮化硼为重点研究对象，构建了分子模型和确定了原子势参数，研究了静/动载荷下的裂纹萌生、扩展、非稳定等力学行为，并计算了静态/动态裂尖场应力分布、能量释放率等。然后，考虑不同的层间扭转角、层数、界面，研究了其在高速弹丸冲击下的动态损伤，并建立了与弹道极限速度、能量耗散效率的关联。最后，二维晶体和碳化硅层叠构建异质复合层，探讨了弹丸侵彻和穿透异质多层材料过程中的冲击能量耗散、动态断裂等物理力学行为，层内应力波扩散、层间相互作用等动力学现象；揭示了类石墨烯晶体增强多维异质复合层抗冲击能力和失效机制，并获得了优化的装甲材料模型。本项目所得结果可为设计新型多维异质复合层、超强韧轻质装甲提供依据，拓展其在军事领域应用。