一种具备可调热膨胀系数的可展开结构的力学特性研究  

RESEARCH ON MECHANICAL PROPERTIES OF THE DEPLOYABLE STRUCTURE WITH ADJUSTABLE THERMAL EXPANSION COEFFICIENT

作　　者：王艳丽 沙振东 佘崇民[3] Wang Yanli;Sha Zhendong;She Chongmin(State Key Laboratory for Strength and Vibration of Mechanical Structures,School of Aerospace Engineering,Xi'an Jiaotong University,Xi'an 710049,China;Laboratory for Novel Disorder Materials,Xi'an Jiaotong University and Taixing Chengxing State Assets Management&Investment Co.,Ltd.,Xi'an 710049,China;College of Aerospace Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China)

机构地区：[1]西安交通大学航天航空学院,复杂服役环境重大装备结构强度与寿命全国重点实验室,西安710049 [2]西安交大-成兴国投无序新材料实验室,西安710049 [3]南京航空航天大学航空学院,南京210016

出　　处：《力学学报》2025年第3期701-711,共11页Chinese Journal of Theoretical and Applied Mechanics

基　　金：国家自然科学基金资助项目(12372116).

摘　　要：在航空航天等领域,结构不仅需要具备精确调控热膨胀系数的能力,以确保在极端温度变化下保持热稳定性,还要具备高效的空间部署能力,以应对受限工作环境中的各种挑战.具备可调特性的点阵复合材料正逐步在工程领域中得到应用.文章结合折纸技术和双材料三角形结构,提出了一种能够实现空间展开、可调热膨胀性能及轻量化的三角形联合可展开结构.通过使用非零厚度面板和调整铰链位置,该结构可以在两侧施加拉力,将理想折纸模型转变为具备承载能力的等效三维结构.进一步通过调整几何参数和材料组合,实现了热膨胀系数从正值到负值的可调性,并能够调节刚度.研究结果表明,增大角度(三角形单元的斜边与对称轴的夹角)和减小厚度比(低、高热膨胀系数材料的厚度比)能有效降低结构的热膨胀系数,同时减小弹性模量.增大单胞比(支撑面与底面的单胞数量比)可以降低结构热膨胀系数并增加弹性模量,但同时会在结构中增加更多易变形的连接部位,从而导致屈服强度下降.减小角度、厚度比和增大单胞比均有利于实现结构的轻量化.结构在承载方向上的等效热膨胀系数的理论值与有限元模拟结果吻合良好.Control of thermal expansion coefficients(TECs)is critical for structural systems in specialized fields such as aerospace,where extreme temperature variation environments necessitate high thermal stability.Meanwhile,such systems also require efficient space deployment capabilities to address the challenges posed by limited working spaces.Lattice composite structures with tunable properties are gradually being applied in the engineering field.In this study,we propose a triangular combined deployable structure that incorporates space deployment,adjustable thermal expansion,and lightweight properties through an origami-based design utilizing bi-material triangles.By introducing panels with non-zero thickness and strategically adjusting the hinge positions,the idealized origami model is transformed into a threedimensional load-bearing configuration when tensile forces are applied to both sides of the structure,allowing it to support loads effectively.The TEC of the structure can be engineered to exhibit either positive or negative values by strategically adjusting the geometrical parameters and material combinations,which also allows tuning of structural stiffness.The results show that increasing the angle(the angle between the symmetry axis and the hypotenuse of the triangle)and reducing the thickness ratio(the ratio of material thicknesses with low and high TECs)can effectively lower the TEC of the structure and simultaneously diminish its elastic modulus.Elevating the cell ratio,which is the ratio of the number of cells on the supporting surface to those on the base surface,decreases the TEC and enhances the elastic modulus of the structure.However,it also introduces more deformable connection regions within the structure,leading to a decrease in yield strength.Additionally,the results indicate that greater improvements in lightweight properties can be achieved by reducing the angle and thickness ratio,as well as increasing the cell ratio.The theoretical values of the equivalent TEC in the load-bearing direction o

关 键 词：空间展开能力 折纸 点阵复合材料 可调热膨胀 

分 类 号：TB331[一般工业技术—材料科学与工程]