[Paper Review] Bio-inspired method based on bone architecture to optimize the structure of mechanical workspieces

Clément Audibert, Julien Chaves‐Jacob+2 more|arXiv (Cornell University)|Oct 26, 2018

Additive Manufacturing and 3D Printing Technologies27 references54 citations

TL;DR

The paper presents a bio-inspired approach, based on bone architecture, to optimize openwork mechanical pieces by controlling porosity via local stress, and compares it to topology optimization via experimental bending tests.

ABSTRACT

Nowadays, additive manufacturing processes greatly simplify the production of openwork workpiece providing new opportunities for workpieces design. Based on Nature knowledge, a new bio-inspired workpiece structural optimization approach is presented in this paper. This approach is derived from bones structure. The aim of this method is to reduce the workpiece weight maintaining an acceptable resistance. Like in bones, the porosity of the part to optimize was controlled by a bio-inspired method as function of the local stress field. Shape, size and orientation of the porosities were derived from bone structure; two main strategies were used: one inspired of avian species and other inspired of terrestrial mammalian. Subsequently, to validate this method, an experimental test was carried out for comparing a topological optimization and the proposed bio-inspired designs. This test was conducted on a beam part in 2.5D subjected to a static three-point bending with 65% of density. Three beams were manufactured by 3D metal printing: two bio-inspired beams (terrestrial mammalian and avian species) and the last designed using a topological optimization method. Experimental test results demonstrated the usefulness of the proposed method. This bio-inspired structural optimization approach opens up new prospects in design of openwork workpiece.

Motivation & Objective

• Motivate lightweight design of openwork workpieces while maintaining acceptable structural resistance.
• Develop a porosity-optimization method inspired by bone structure driven by local stress fields.
• Derive porosity shape, size, and orientation from avian and terrestrial mammal bone strategies.

Proposed method

• Use bone-inspired principles to control porosity in the part as a function of local stress.
• Derive porosity geometry (shape, size, orientation) from avian and terrestrial mammal bone structures.
• Fabricate beams by 3D metal printing in three variants (two bio-inspired, one topology-optimized).
• Test beams under static three-point bending at 65% density to assess performance.

Experimental results

Research questions

• RQ1 Can a bio-inspired porosity design based on bone architecture reduce weight while preserving resistance compared to topology-optimized designs?
• RQ2 How do avian-inspired and terrestrial mammal-inspired porosity patterns perform under bending load?
• RQ3 What is the feasibility of implementing bone-derived porosity in additively manufactured openwork parts?

Key findings

• Experimental tests show the bio-inspired designs are useful for openwork structures under bending, with performance compared to topology optimization.
• Three beams were printed: two bio-inspired (terrestrial mammalian and avian) and one topology-optimized, all at 65% density.
• The results validate the usefulness of the proposed bone-architecture-based optimization approach.