Leaf-vein-inspired fiber-matrix composites with graded chevron architectures

Area of Science:

• Materials Science
• Mechanical Engineering
• Biomimetics

Background:

• Nature-inspired designs offer novel solutions for material engineering.
• Fiber-matrix composites with complex architectures are gaining attention for advanced applications.
• Functionally graded materials allow for tailored mechanical and thermal responses.

Purpose of the Study:

• To design and evaluate bio-inspired fiber-matrix composites with chevron architecture and graded fiber orientations.
• To engineer materials with enhanced mechanical characteristics under mechanical and thermal loads.
• To explore the design space for auxeticity and tune effective properties.

Main Methods:

• Development of finite element (FE) models of representative volume elements (RVEs).
• Extensive parametric studies to investigate effective mechanical properties.
• Multi-material 3D printing for fabricating specimens.
• Uniaxial tension, three-point bending, and thermal stress experiments.

Main Results:

• Varying fiber orientation tunes effective stiffness and Poisson's ratio across a broad range.
• Auxetic designs (positive and negative Poisson's ratios) were successfully fabricated and tested.
• FE simulations and experiments confirmed the tunability of mechanical properties.
• Auxetic designs demonstrated higher ductility and reduced thermal stress.

Conclusions:

• Bio-inspired composites with chevron architecture and graded fiber orientations offer significant potential for enhanced performance.
• The developed design methodology allows for precise tuning of mechanical and thermal properties.
• Auxetic materials derived from this approach show promise for applications requiring high ductility and thermal stress mitigation.