高g值冲击下多交织相泡沫金属填充壳动力响应及耗能机理研究

Multi-interpenetrating phase composite (MIPC) foam which is composed of metal foam and porous polymer is a novel function material with high damping and efficient energy absorption performance. It can efficiently compensate the shortage of traditional metal foam in the protection for strong impulse and high G multi-shock in confined space and has potential application value at impact cushioning of light mass devices in projectile-rocket structure. Hence, dynamic response and energy absorption mechanism of MIPC foam and its composite structure under intensive dynamic loading is exigently worth researching. Based on mechanics experiments and theoretical analysis, this research aims to establish quantitative relation between the mechanical property and the composite component, and constitutive model of MIPC aluminum foam filled with porous silicon rubber, reveals the mechanism of its strain rate effect. It is also designed to develop and improve the plastic dynamical analytical model of MIPC foam filled shell subjected to axial impact, study the microscomic damage/failure model and dynamic cushion mechanism of MIPC foam and its filling thin-shell by SEM observation, high-speed photography and digital image correlation (DIC) technique. With the specific energy absorption (SEA) and the ratio of peak caution acceleration to the incentive acceleration as the optimization objective, the multi-objective optimization will be performed at the geometrical parameters of composite structure by means of numerical simulation, design of experiment (DOE) and the response surface model (RSM). Effect of key design parameters on structural cushion performance and mechanical response will be identified to develop a corresponding evaluation criterion. It will enrich the application of the new high-performance metal foam in impact cushioning of light mass devices for military industry and furtherly afford the theoretical foundation and technical support.

多孔高聚物填充泡沫金属而成的多交织相复合（MIPC）泡沫金属可有效弥补普通泡沫金属在有限空间内、抗多次、强冲击时能量吸收方面的不足，在弹载轻质元件缓冲防护方面极具应用价值，MIPC泡沫及其填充结构在强动载荷下的动力响应和耗能机理亟需研究。本项目通过动力学实验和理论分析，建立泡沫铝基多孔硅橡胶填充的MIPC的力学性能与组元参数间的定量关系及本构模型，揭示其应变率效应产生机理。发展和完善MIPC填充壳轴向冲击塑性动力学模型，结合SEM、高速摄影和数字图像相关技术全面了解复合结构的细观损伤/失效机制和缓冲机理。基于数值模拟、实验设计和响应面代理模型，以比吸能、缓冲加速度与激励加速度比值为目标，对结构关键参数进行多目标优化设计，揭示关键参数对缓冲性能和力学响应的影响规律，形成相应的评估准则。为新型高性能泡沫金属在军用轻质元器件的高g值被动冲击防护中的应用提供基础理论依据和技术支持。

金属骨架和多孔高聚物构成的多交织相复合泡沫具有高比性能、抗多次冲击等优异性能，在弹载轻质元件缓冲防护方面极具应用价值。本项目采用压力渗透法制备了两类多交织相复合泡沫（IPCs和CPSFs），分析了材料微观组织结构并构建了孔隙率模型，通过静动态力学特性实验考察了材料密度、增强相和构型对其关键力学性能的影响规律，在Avalle模型基础上引入应变率效应和Weibull函数构建了静动态本构模型，结合SEM和DIC技术分析材料失效机制发现，CPSFs在低速压缩下主要产生剪切失效，高速冲击下产生轴向劈裂失效，通过添加铝基约束，材料在低速和高速加载下均表现为轴向压缩失效，表明铝基不仅可以增强材料力学性能还能够改善静动态力学行为。通过内嵌薄膜式压力传感器测量了CPSFs内部不同截面的应力时程曲线，研究了材料局部变形特征和应力波在多孔多相介质中的传播、衰减以及局部集中增强的规律。然后，结合数值模拟研究CPSFs填充壳在不同加载工况下力学响应，结果表明复合结构中耦合效应主要体现在泡沫填对薄壳变形稳定性的改善和承载能力的提升（~10%）。基于超折叠单元构建了预测泡沫填充壳缓冲加速度的理论模型，通过四阶多项式响应面和多目标优化算法获得了针对弹体侵彻硬目标产生的激励加速度的最优结构形式，发现NSGA II相比于理想点法可在更大目标范围内提供更多最优解。