Structural additive manufacturing parts bio-inspired from trabecular bone form-function relationship

Abstract

Mass reduction and strength-to-weight optimisation are of increasing interest in mechanical engineering. Natural materials such as bone face the same challenges and strike an optimal balance between weight and mechanical performance. Several approaches sought to reproduce trabecular bone’s mechanical efficiency, for example topology optimisation or cellular materials. These approaches are often restricted by their computational cost or their spatial homogeneity. Here we develop a 3D mass reduction method bio-inspired from trabecular bone that provides both fast computation and stress driven architecture. The mass reduction method is based on a bio-inspired porous pattern. The pattern is locally adapted to the estimated stress in a mechanical part through an algorithm. This results in an optimised porous architecture that mimics the trabecular form-function relationship. This 3D mass reduction method was validated through 3-point bending experiments. At equal mass, the proposed method showed 66 % improvement in bending stiffness compared to a 2.5D bio-inspired method and 111 % improvement compared to a topology optimisation method. Our results demonstrate the potential of the proposed method for strength-to-weight optimisation. It is applicable in various industries to lighten parts, reduce raw material usage, design composite sandwich cores or personalised bone-tissue scaffolds.

Keywords

• Mass reduction method
• Bio-inspiration
• Trabecular bone
• Fabric Tensor
• Volume Fraction