Limit states of cellular metals under multiaxial loading have been investigated. Torsional, shear, tensile and combined loads were applied to understand the multi-axial response of metallic foams. The goal is to develop computational models for virtual experiments and the computer aided design of components made of cellular or lattice materials.
We have also carried out compressive tests of metallic foam samples at elevated temperatures ranging from 200 to 700 C to understand the effect of temperature on Young modulus and yield stress. Cellular materials have a larger surface area, and oxidation has a higher impact than on the bulk materials.
Damping materials such as rubber have relatively low stiffness, while rigid materials such as steel have relatively low damping. Our aim has been to create a material that is both stiff and exhibits high damping. We have achieved promising results using an architected lattice material with a load carrying frame and floating, damping fibres. Optimisation work is ongoing on fine tuning and finding Pareto front architectures for various combination of the desired stiffness and damping.
We have developed a miniaturise wind tunnel to test permeability and Forchheimer constant of open-cell metallic foams and architected lattice materials.
Our group has also been studying the potential of highly controllable permeability for passive flow control. We have carried a series of tests for various material architectures and configurations with a focus on the flow around a cylinder.