GAM: General Auxetic Metamaterial with Tunable 3D Auxetic Behavior Using the Same Unit Cell Boundary Connectivity

Area of Science:

• Materials Science
• Mechanical Engineering
• Metamaterials

Background:

• Auxetic metamaterials exhibit a negative Poisson's ratio, offering superior impact resistance and actuator capabilities.
• Existing auxetic materials struggle with effect grading, material integration, isotropic transverse behavior, and design adaptability.

Purpose of the Study:

• To present a novel, tunable 3D metamaterial capable of achieving a broad spectrum of auxetic and non-auxetic Poisson's ratios and Young's moduli.
• To address limitations in current auxetic metamaterial designs through a versatile unit cell geometry.

Main Methods:

• Development of a patented tunable 3D metamaterial based on a single unit cell geometry.
• Modification of internal node connectivity and positions to achieve diverse mechanical properties.
• Utilizing simple spatial triangularization for scalability and adaptability to complex boundaries.

Main Results:

• The proposed metamaterial successfully reproduces a wide range of 3D auxetic and non-auxetic behaviors.
• Functionally graded metamaterial designs are facilitated by altering only node connectivity and positions.
• The metamaterial demonstrates scalability and improved accommodation of spatial curvatures and component boundaries.

Conclusions:

• The novel 3D metamaterial offers a versatile solution for advanced applications requiring tunable mechanical properties.
• The design overcomes key challenges in auxetic metamaterial development, enabling broader integration and customization.
• This approach simplifies the design of functionally graded metamaterials and enhances adaptability to complex geometries.