# Design of Bi-Material Triangle Curved Beam Honeycomb Metamaterial with Tunable Poisson’s Ratio, Thermal Expansion, and Band Gap Characteristics

## TL;DR

This paper introduces a new honeycomb metamaterial design that can adjust its mechanical and thermal properties for use in aerospace and automotive applications.

## Contribution

A novel bi-material triangular curved beam honeycomb metamaterial with tunable Poisson’s ratio, thermal expansion, and band gap characteristics is proposed.

## Key findings

- The BTBM design allows simultaneous tuning of Poisson’s ratio, CTE, and band gap through geometric and material adjustments.
- Finite element simulations validated the band gap characteristics and transmission behavior of the metamaterial.
- Parametric optimization significantly enhances the tunability of mechanical properties.

## Abstract

Metamaterials, owing to their exceptional properties such as a negative Poisson’s ratio, phonon band gap, and energy absorption, have garnered significant interest in aerospace, automotive transportation, and other domains. The increasing demand for metamaterial structures with diverse specialized attributes requires innovative design approaches. In this study, a novel bi-material triangular curved beam honeycomb metamaterial (BTBM) is designed, which exhibits a tunable Poisson’s ratio (PR), coefficient of thermal expansion (CTE), and band gap characteristics. These properties are intrinsically coupled through the geometric and material design of the bi-material triangular curved beam structure, meaning that adjustments to the unit cell configuration simultaneously influence PR, CTE, and band gap behavior. This dual-mode control offers versatile design strategies for multifunctional metamaterials. The energy band structure is calculated using finite element simulation analysis, and its accuracy is validated by computing the transmission characteristic curve. Numerical simulations were performed to systematically analyze the coupled effects of geometric parameters and material combinations on the PR and CTE. The results demonstrate significant tunability of these mechanical properties through parametric optimization. The results of this study provide valuable insights into the design and optimization of metamaterial structures with tailored properties for various applications.