形状记忆聚合物异质手性超结构的力学设计、变形机理及实验表征

Owing to their unique geometric topology, chiral superstructures have supernormal mechanical properties such as negative Poisson's ratio, pressure-torsional coupling response and negative thermal expansion, and have great application potential in flexible and intelligent industrial structures. At present, most of the chiral superstructures are made of traditional materials. As a result, the functions of self-driving deformation, solidification and variable stiffness of the structure cannot be realized. Based on 4D printing technology, shape memory polymer (SMP) constitutive model and finite element method, this project designs and obtains an innovative configuration of chiral superstructure with shape memory and variable stiffness by developing SMP heterogeneous chiral superstructure mechanical design method. By developing the deformation theoretical model of superstructure, the constitutive relation between deformation behavior and functional response function is established, revealing the driving deformation mechanism and variable stiffness design principle of the superstructure. A platform is established to quantitatively characterize the functional response supernormal deformation behavior of the superstructure under thermal-mechanical coupling, thus provided mechanical experiments, characterization and evaluation methods for the study of super-deformation behavior of structures. The implementation of this project will lay a solid foundation for the mechanical design, deformation mechanism and experimental characterization of SMP heterogeneous chiral superstructures.

手性超结构因其独特的几何拓扑结构，具有负泊松比，压-扭耦合响应和负热膨胀等超常力学行为，在柔性与智能工业结构中具有巨大的应用潜力。目前，大多数手性超结构采用传统材料制作，无法实现结构的自驱动变形、固形和变刚度的功能。本项目基于4D打印技术和形状记忆聚合物（SMP）本构模型及有限元法，发展SMP异质手性超结构力学设计方法，设计并获得具有形状记忆与变刚度功能的创新构型手性超结构。通过发展超结构的变形理论模型，建立其变形行为与功能响应函数之间的本构关系，揭示该结构的驱动变形机理与变刚度设计原理。搭建热-力耦合作用下超结构功能响应超常变形行为的定量化表征平台，进而为结构超常变形行为的研究提供力学实验、表征与评价方法。本项目的实施最终为SMP异质手性超结构的力学设计、变形机理及实验表征研究奠定坚实基础。

力学超结构及超材料是一种人工设计的周期性或非周期性材料与结构，具有超越天然材料属性的力学性能，在柔性、智能工业结构中具有巨大的应用潜力。目前，大多数超结构采用传统材料制作，无法实现结构的自驱动变形、固形和变刚度的功能。形状记忆聚合物（SMP）是一种在外界刺激条件下产生形状变化的智能材料。4D打印是一项基于可变形材料和3D打印技术的综合技术。本项目基于4D打印技术和SMP材料，针对4D打印的SMP试件开展一系列动、静态力学试验，测试材料的玻璃化转变温度、不同温度下应力-应变曲线、弹性模量，发展适用于4D打印SMP力学响应本构模型和有限元程序，利用SMP材料特性和有限元程序发展SMP超结构力学设计方法，设计并获得具有形状记忆效应和变刚度功能的创新构型多功能超结构。通过发展超结构的变形理论模型，建立其变形行为与功能响应函数之间的本构关系，揭示该结构的驱动变形机理和变刚度设计原理。搭建热-力耦合作用下超结构功能响应超常变形行为的定量化表征平台，进而为结构超常变形行为的研究提供力学实验，表征和评价方法。本项目的实施最终为SMP多功能超结构的力学设计、变形机理及实验表征研究奠定坚实基础。