Tailoring the compressive properties of 3D printed composites using bioinspired micro/macrostructure designs

Area of Science:

• Materials Science
• Composite Materials
• Mechanical Engineering

Background:

• Natural composites exhibit superior mechanical properties due to hierarchical designs.
• Fabricating complex, high-performance man-made composites remains challenging.
• 3D printing and shear forces offer new fabrication possibilities for microstructured hierarchical composites.

Purpose of the Study:

• To 3D print glass microfiber-reinforced composites in Bouligand structures.
• To investigate the mechanical properties of bulk and lattice Bouligand composites.
• To explore the role of micro/macrostructure design in enhancing composite performance.

Main Methods:

• 3D printing of glass microfiber-reinforced composites.
• Fabrication of porous Bouligand structures with lattice designs.
• Mechanical testing (compressive stress, energy absorption) and fracture analysis.
• Numerical simulations for stress distribution analysis.

Main Results:

• Bulk Bouligand composites showed maximum compressive stress (117 MPa) and energy absorption (19 MJ/m³) at a 40° pitch angle.
• Lattice Bouligand composites with 25-50% porosity exhibited superior performance at a 90° pitch angle.
• Identified crack twisting and bridging in bulk composites, and radial crack propagation with bridging in lattice structures.

Conclusions:

• Micro/macrostructure design critically influences compressive strength, modulus, and energy absorption.
• Bouligand lattice structures offer a promising design for lightweight, high-strength, energy-dissipating composites.
• Findings are relevant for aerospace, architecture, and defense applications.