超弹性人工材料设计与波动特性研究

超弹性材料是一种典型的非线性弹性材料，不仅有望解决航空航天、软机器人等领域对大变形非线性弹性行为的需求，还可通过预应力调控为弹性波传播提供独特的控制方式。但目前缺乏相应微结构设计的系统方法，已成为制约该类材料研制的瓶颈问题。本课题基于橡胶材料超弹性行为微观机制的启发，通过构造曲梁人工分子链单元，组装构建分子链网络型超弹性人工材料，并发展相应的微结构设计和宏观性能表征方法。课题主要研究内容包括：（1）由给定载荷-位移函数反演人工分子链构型的反问题解决方法；（2）超弹性点阵网络的宏观等效应变能密度与连接布拉菲格点弹性介质的载荷-位移函数之间的解析关联；（3）典型理想超弹性材料如semi-linear材料的人工微结构实现及波控功能设计。通过理论、数值和实验相结合的途径，系统解决如何根据预期超弹性宏观性质设计人工材料的难题，提升面向大变形弹性响应需求的功能-材料-结构一体化设计基础研究水平。

Hyper-elastic material is a kind of typical nonlinear elastic materials, which is not only expected to solve the demand of nonlinear elastic large deformation behavior in aerospace, soft robotics and other fields, but also can provide a unique control method for elastic wave propagation through prestress regulation. However, the lack of systematic method for the corresponding microstructure design has become a bottleneck problem restricting the development of this kind of materials. Based on the inspiration of the micro mechanism of the hyper-elastic behavior of rubber materials, this project proposes a method to design hyper-elastic artificial material through constructing the artificial molecular chain unit (curved beam), assembling and constructing the molecular chain network. The main research contents of this project include: (1) optimization design method for the inverse problem of obtaining the artificial molecular chain geometry for given load-displacement function; (2) the analytical relationship between the macroscopic equivalent strain energy density of the hyper-elastic lattice network and the load-displacement function of the elastic medium used to connect the lattice Bravais points; (3) the realization scheme of artificial microstructure and the design of wave control function of typical ideal hyper-elastic materials such as semi-linear materials. Through the combination of theory, numerical and experimental methods, the project will systematically solve the problem of how to design artificial materials according to the expected macroscopic hyper-elastic properties, and elevate to a large extent the research on the function-structure-material integration design of engineering applications where nonlinear elastic large deformation behavior is required.