A novel 3D structure with tunable Poisson's ratio and tailorable coefficient of thermal expansion based on a tri-material triangle unit. (1st December 2020)

• Record Type: Journal Article
• Authors: Chen, Ming-Ming; Fu, Ming-Hui; Lan, Lin-Hua; Sheshenin, Sergey V.
• Is Part Of: Composite structures. Volume 253(2020)
• Publication Date: 2020-12-01
• Subjects: Auxetic materials -- Tri-material triangle unit -- Tailorable coefficient of thermal expansion -- Equivalent formulas -- Numerical simulation verification; Composite construction -- Periodicals; Composites -- Périodiques; 624.18
• DOI: 10.1016/j.compstruct.2020.112803
• Languages: English
• ISSNs: 0263-8223

Abstract

Highlights: This paper proposes a three-dimensional structure based on a triangle unit. The analytical formulas for PR and CTE are given. This structure can achieve both negative PR and negative CTE. The mechanism can be regarded as a new concave angle mechanism. Abstract: Auxetic materials and negative thermal expansion materials show great application potential in many important fields. In this paper, a novel three-dimensional truss structure with a tunable Poisson's ratio and tailorable coefficient of thermal expansion was developed. Since the deformation of each rod was dominated by axial tension or compression, the structure showed high stiffness. Equations regarding equivalent elasticity parameters and coefficients of thermal expansion of the structure were obtained by displacement and unit force methods. A numerical simulation verification was performed by ANSYS 16.0 software. The verification results indicated that the formulas have high precision and wide application scope. Through parametric analysis, we obtained the conditions for achieving a negative Poisson's ratio and negative thermal expansion coefficient. We also concluded that this material could realize a three-dimensional negative Poisson's ratio and bidirectional negative thermal expansion simultaneously by choosing reasonable geometric parameters and material combinations.