A new design of dual-constituent triangular lattice metamaterial with unbounded thermal expansion

作     者：Y.C.Zhang Y.J.Liang S.T.Liu Y.D.Su 

作者机构：State Key Laboratory of Structural Analysis for Industrial EquipmentDalian University of TechnologyDalian 116024China New Functional Structural Design and Verification Key Laboratory of Aeronautical TechnologyShenyang 110035China 

出 版 物：《Acta Mechanica Sinica》 (力学学报（英文版）)

年 卷 期：2019年第35卷第3期

页      面：507-517页

核心收录：

学科分类：08[工学] 0802[工学-机械工程] 0701[理学-数学] 0801[工学-力学（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：the National Natural Science Foundation of China (Grants 11332004 and 11572071) 111 Project (Grant B 14013) CATIC Industrial Production Projects (Grant CX Y2013DLLG32) the Fundamental Research Funds for the Central Universities (Grant DUT18ZD103) 

主　　题：Metamaterial Zero thermal expansion Lattice material Multifunctional design Additive manufacturing 

摘      要：Triangular lattice metamaterials composed of bi-layer curved rib elements (called the Lehman-Lakes lattice) possess unbounded thermal expansion, high stiffness and impossibility of thermal buckling, which are highly desirable in many engineering structural applications subjected to large fluctuations in temperature. However, the requirement of such lattice metamaterial is that it must be a hinged joint in order to achieve the bending deformation upon heating freely, which directly leads to poor manufacturability, especially in small dimensions. In this study, a new design of dual-constituent triangular lattice metamaterial (DTLM) with good manufacturability is proposed to achieve the identical unbounded thermal expansion. In this lattice, a special bi-layer curved rib element where layer one is partially covered by layer two is presented, where the hinge joints are not necessary because the flexural rigidity in the single-layer part is much smaller than that in the bi-layer part, and the desirable thermal bending deformation can be achieved. A sample fabricated by additive manufacturing is given in order to show the good manufacturability;simultaneously, the multifunctional performance of the tailored DTLM with zero, large positive or negative coefficient of thermal expansion (CTE) can remain excellent, as well as the Lehman-Lakes lattice. Examples illustrate that the DTLM with zero CTE has about 34.2% improvement in stiffness and meanwhile has 17% reduction in weight compared with the Lehman-Lakes lattice. The stiffness of the DTLM has a moderate reduction when achieving the same large positive or negative CTE. In addition, the thermomechanical properties of the DTLM are given by the closed-form analytical solution and their effectiveness is verified by the detailed numerical simulation.