Optimally-tailored multiscale porous materials: From mathematics-based design to engineering applications

Li, Zeyang 2024. Optimally-tailored multiscale porous materials: From mathematics-based design to engineering applications. PhD Thesis, Cardiff University. Item availability restricted.

Preview	PDF (Thesis) - Accepted Post-Print Version Download (29MB) | Preview
	PDF (Cardiff University Electronic Publication Form) Restricted to Repository staff only Download (633kB)

Abstract

Previous works on porous materials have often focused on isotropic, periodic tesselated structures due to the manufacturing limitations. However, recent advancements in additive manufacturing have made it possible to create more intricate porous materials featuring multi-scale structures and enhanced functionality. There has been a significantly increased interest by researchers in this field, over the past few years. This thesis presents two novel design methods for advanced multifunctional porous materials with nature-inspired geometries and programmable material properties, e.g., anisotropic elasticity or multi-functionality. This thesis introduces two bio-inspired design methods for multi-scale porous materials: the variable-periodic Voronoi tessellation (VPVT) method and the varied-shape Voronoi tessellation (VSVT) method, as presented in Chapter 3 and Chapter 4, respectively. The VPVT method produces a meso-macro multiscale porous structure characterized by sparse truss struts. By combining fractal design with strategic Voronoi-seed placement, it creates diverse lattice designs that enable physical and metamaterial properties. In contrast, the VSVT method applies a micro-macro multiscale design approach based on Riemann metric transformations of Voronoi architectures. It results in deformed cell shapes with tunable anisotropic elasticity, directional material properties, and adjustable porosity. The highly design flexibility of VSVT allows for tailoring material with varying specific surface areas, make it particularly advantageous for optimizing thermal transfer and enhancing bio/chemical reaction rates. Overall, both methods incorporate local anisotropic topology, to achieve high natural similarity, strong connectivity and superior global stiffness. The proposed methods provide general workflows for advanced material design, which are applicable in various fields. Chapter 5 and Chapter 6 illustrate practical applicaii tions of these methodologies to validate their effectiveness. Chapter 5 presents a flapping wing design, inspired by dragonfly wings, using VPVT method. The design demonstrate improvements in stiffness, frequency response, and aerodynamic performance, confirmed through finite element method (FEM) simulations. Chapter 6 presents a hip implant design developed with the VSVT method. The final design not only shows high stability, but also achieves reduced stress shielding and minimized bone loss compared to conventional modes, thereby lowing the risk of revision surgery

Item Type:	Thesis (PhD)
Date Type:	Completion
Status:	Unpublished
Schools:	Schools > Engineering
Date of First Compliant Deposit:	11 April 2025
Last Modified:	11 Apr 2025 14:25
URI:	https://orca.cardiff.ac.uk/id/eprint/177610

Actions (repository staff only)

Edit Item