新型轻质点阵材料热膨胀调控设计、制备与表征

Due to severe temperature variation in service environment of aerospace engineering, precise control of the thermal expansion deformation of various structures in satellites and hypersonic vehicles is urgently needed. However, the present bulk materials and composites can not simultaneously satisfy the multiple requirements of tailorable thermal expansion, lightweight characteristic as well as excellent mechanical properties. By taking advantage of the lightweight and robust mechanical properties of the lattice material, this project aims to innovatively propose novel lattice material which incorporates lightweight characteristic, excellent load bearing capacity as well as tailorable thermal expansion. This project firstly focuses on developing a generalized design method to obtain tailorable thermal expansion for novel lattice material. Design method will also be proposed to develop multi-level novel lattice material for much wide range of tailorable thermal expansion. Mechanical properties, including elastic constitutive relation, failure models and failure mechanism will be investigated. Moreover, optimal design method and fabrication process for the novel lattice material will be investigated and established. Finally, the key thermal and mechanical properties of the novel lattice material will be characterized. The essential properties, such as thermal expansion, strength and stiffness under temperature variation and thermomechanical coupling service environment will be revealed. The obtained results in this project are very promising to provide new solution, theoretical design method and experimental basis for aerospace engineering structures which urgently require materials with tailorable thermal expansion, lightweight characteristic as well as robust mechanical properties.

在温度剧烈变化服役环境下，航空航天工程中卫星、高超声速飞行器的大量结构的热膨胀变形需要精确地调控。然而现有的均质及复合材料均难以同时满足结构对热膨胀可调控且兼具轻量化，力学性能优异的多重需求。本项目结合点阵材料轻质，力学性能优异的优点，创新地发展轻质-承载-热膨胀可调控一体化新型点阵材料。项目首先重点建立新型轻质点阵材料的热膨胀调控设计方法，并研究多级新型点阵材料设计方法以实现热膨胀大范围调控设计。建立和获得新型点阵材料的弹性本构关系，失效模式及失效机理等力学性能。其次开展新型点阵材料的优化设计与制备技术研究。最后针对新型点阵材料的关键热学及力学性能进行表征，揭示其在温度变化和热力耦合服役环境下的热膨胀、强度，刚度等重要性能，为航空航天工程中结构对热膨胀可调控且兼具轻量化，力学性能优异新材料的迫切需求提供新的解决方案，理论设计方法及实验依据。

在温度剧烈变化服役环境下，航空航天工程中卫星与高超声速飞行器的大量结构的热膨胀变形需要精确地调控。本项目结合点阵材料轻质及优异力学性能的优点，创新地设计发展了一类轻质-承载-热膨胀可调控一体化新型点阵材料。本项目首先完成了新型三维点阵材料设计，实现了三维空间热膨胀系数调控，并提出三维空间不动点法可将任意空间结构重构而具有所需的热膨胀系数。同时基于平面点阵材料，以卷曲方法设计了多类多种点阵圆柱壳结构，实现了轴向和径向热膨胀系数的宽幅调控。在此基础上设计了热膨胀及泊松比可同时集成调控的新型点阵材料，拓展了点阵材料的功能集成化。进一步组建了基于数字图像相关法的非接触式热膨胀系数实验测试系统。探索采用增材制造工艺制备了双组分的点阵材料，并通过热膨胀系数实验测试，证明所制备的点阵材料可实现热膨胀系数的宽幅调控。本项目的研究成果为航空航天工程中结构对热膨胀可调控且兼具轻量化，力学性能优异新材料的迫切需求提供新的解决方案，理论设计方法及实验依据。