多孔格栅填充金属薄壁复合结构轴向冲击形性演变机理及失稳控制

Vehicle crash safety has become a worldwide major problem. Composites thin-walled structure filled with cellular lattice (CSFL) has been a new hot topic in design of special energy absorption device due to its outstanding loading-carrying and excellent energy absorption properties. This project focuses on the problem of dynamic response mode of CSFL in diversity, complexity, divergence, wide service condition and controllable design. The theoretical methodology, quasi-static and dynamic experiment would be employed. The main research contents are: interaction mechanism and coupling effect between inside and outside structures, dynamic theoretical model and the deformation properties evolution mechanics, matching effect between inside and outside structures as well as its matching model and instability control. At the same time, three key scientific problems would be worked out on decoupling analyses between inside and outside structures, characterization of the rate-dependent theoretical energy absorption model and reasonable matching problem. Through the above research works, some dynamic theoretical models combined with cell periodic law and geometric configuration would be constructed. In addition, deformation properties mechanics evaluating with the impact velocity, geometric topology and matrix material would be determined. Corresponding matching criterion would be constructed, and strategies for model instability control would be put forward. All these achievements provide significant theoretical guidance for reasonable, efficient and robust design of energy absorption device with lightweight, high strength and excellent specific energy absorption.

运载工具碰撞安全已成为世界性主要问题，多孔格栅填充金属薄壁复合式结构兼备高强承载、高效吸能特性，成为新型专用吸能装置设计热点。项目针对多孔格栅填充薄壁复合结构动态冲击响应模式的多样性、复杂性、发散性、服役环境宽、可控设计难等问题，综合采用理论建模、准静态实验、动态冲击实验和数值仿真相结合的方法，从填充结构内外两元相互作用机理及耦合效应、填充结构动态冲击理论模型及形性演变机制、内外两元匹配设计优化与失稳模式控制三方面展开研究，解决填充结构内外两元解耦分析、率相关动态冲击理论吸能模型表征、内外结构匹配三大关键科学问题，建立反映格栅胞元周期规律、细观构型的填充结构动态冲击理论吸能模型，构建耦合冲击速度、几何拓扑、材质属性等多元参数在内的填充结构形性演变规律图谱，建立最优匹配准则，提出复杂服役环境下填充结构模式失稳控制方法，为轻质高强高比吸能装置的合理、高效、稳健可控设计提供理论指导。

为实现运载工具专用防护装置轻质、高强承载和高效吸能的目的，本项目完成了多孔格栅填充金属薄壁复合结构轴向冲击形性演变机理及失稳控制研究。主要以蜂窝为例，采用理论推导、数值仿真和实物实验相结合的方法，先后建立了反映周期元重复规律、细观拓扑构型的多孔格栅理论吸能模型和薄壁方管非线性塑性偏心屈曲历程及耗能理论模型，探明了填充结构相互作用区域由疏至密的动态响应模式及力学分区方法，研究了填充结构在压溃、塑性坍塌和渐进屈曲时对其总体吸能力学行为的影响。利用全尺度格栅结构精细数值模型构建及动态冲击仿真方法，研究了外围薄壁结构和内充格栅相互作用的刚度强度匹配特性，并用准静态实验和动态冲击实验进行了模型验证，进一步研究了微角度偏载、结构缺陷、弹性受载条件和初始应力诱发的失稳模式及控制结构方法。本项目已累计发表SCI论文14篇，其中国际权威JCR一区论文13篇，含2篇ESI高被引论文，申请了国家发明专利3项，超额完成了预期成果要求。