温度敏感各向异性材料的表面失稳机理和微结构拓扑优化研究

温度敏感材料是指在温度变化时能够改变自身特性如几何形状，导热系数，膨胀系数，折射率的高分子材料，可用于高分子温敏传感器、调光结构和形状记忆结构的制造。本项目针对由温度敏感复合材料构成的复杂曲率的曲面结构和多孔结构，建立温度场或热力耦合作用下的失稳控制方程，研究材料的弹性模量、泊松比和蠕变应变在玻璃化转变温度中的变化。研究层合结构表面失稳的各种模态以及后屈曲过程中出现的曲率二次分岔和局部失稳现象，并通过叠加几何缺陷研究反向表面失稳过程中的形貌演化机理。提出具有光滑边界的双向渐进结构优化算法以实现温度敏感材料的微结构优化，设计具有各向异性膨胀性能和负热膨胀的复合材料以控制结构表面失稳和形貌演化。该温度敏感智能结构在自适应环境建筑、柔性电子元件和药品输送等领域具有良好的应用前景。

Thermal-sensitive materials refer to the polymer materials can change their properties such as geometry, thermal conductivity, coefficient of expansion and refractive features under temperature changing. They can be used for fabricating thermal-sensitive sensor, dimming structures and shape memory structure. This project aims at investigating the thermal-sensitive structures with composite curvatures and porous surfaces, deriving the governing equations affected by temperature field or thermal mechanical coupling field, and studying the changing of elastic modulus, Poisson’s ratio and creep of the material at the glass transition temperature. The project also classifies the forms of instability, secondary bifurcation and local instability during the post buckling process. The reverse post buckling process is studied by superpositioning geometrical imperfection. Additionally, the bi-directional evolutionary structural optimization with smooth boundaries algorithm is proposed to realize microstructure optimization of the thermal-sensitive materials and design composite materials with anisotropic expansion properties or negative thermal expansion ratio, which can control structure surface instability and morphology evolution. The methodology of designing thermal- sensitive intelligent structures can have good application prospect in adaptive environment constructions, flexible electronics and drug delivery.