周期性复合材料的元胞结构和材料参数的抗撞性优化设计研究

Energy conservation and emissions reduction is the main direction for the vehicle development, while the lightweight design of car body is respectively an effective way to realize it. It is inevitable to search for a type of light and environmental material be satisfied with the safety requirement during vehicle development. Composite material is a new automobile body material with dual purpose of structural materials and functional materials. It has not only the light, high temperature resistance, fatigue resistance, corrosion and other excellent properties, but also has characters of higher specific strength, specific modulus, impact resistant and energy absorption characteristics than metal materials. The energy absorption characteristics of composite structures depends on not only the layer order, form, performance of fibers and matrix in macroscopic aspect, etc., to a large extent depends on the control of cellular structure in mesoscopic consideration. The project is to make a further study on representative volume element of periodic composite materials by means of theoretical derivation, numerical simulation and experiment validation, to reveal the mechanism of failure modes and energy absorption of composite periodic structure and to put forward effective analysis and optimization method for crashworthiness design of composite structures, so as to implement the designability of periodic composites applied on car body based on the requirement of material properties.

节能减排是汽车发展的主要方向，车身轻量化是实现节能减排的有效途径；寻找满足碰撞安全性设计要求的轻质环保材料，成为汽车行业发展的必然趋势。复合材料是具有结构材料和功能材料双重用途的新型车身材料，不但具有轻质、耐高温、耐疲劳、抗腐蚀等优良性质，而且具有比金属材料更高的比强度、比模量、抗冲击和能量吸收特性。复合材料结构的吸能特性不但依赖于复合材料宏观的铺层顺序、形式、纤维和基体性能等，很大程度上依赖于对细观元胞的结构控制。本项目拟通过采用理论推导、数值模拟和试验验证的手段，深入研究周期性复合材料的代表性体积元，揭示复合材料周期性结构的失效模式和吸能机理，提出复合材料结构抗撞性分析和优化设计的有效方法，实现基于属性要求的车身用周期性复合材料的可设计性。

针对非线性均质化理论和多种周期性复合材料，开展以下研究：基于迭代法的非线性均匀化方程的数值解法，推导了非线性弹性多尺度均质周期性复合材料的均质化方程，包括周期性金属基颗粒增强复合材料均匀化；采用实验的方法对自然界中的天然复合材料进行了多尺度研究，包括周期性生物材料为夹芯、复合材料为面板的新型夹层结构；开展了周期性复合材料夹层结构低速冲击下的实验和仿真研究，包括周期性瓦楞夹层结构和三明治结构的动态能量吸收机理和优化设计；进行了缠绕成型周期性复合材料吸能结构的抗撞性研究，并研究了纤维铺层方式和铺层角度对周期性复合材料吸能结构的影响；提出了一种基于碰撞安全性考虑的车身材料结构的一体化设计方法。上述研究对周期性复合材料的推广应用具有重要的指导意义。