Research Projects

Sandwich panels are widely used in aerospace, transport, and sports industries due to their lightweight and enhanced properties. Researchers have been exploring the development of auxetic structures as cores in sandwich panels due to their enhanced mechanical properties due to their negative Poisson's ratio (NPR). The Poisson's ratio depends on geometrical parameters such as wall thickness, length, and angles of unit cells. Several attempts have been made to modify existing auxetic structures or combine their geometric features. Combining these geometric features has proven to be a promising method for developing new auxetic structures with improved performance. A new auxetic structure is planned to be developed by combining the geometric features of existing structures and optimizing their geometrical parameters. The deformation mode, NPR, stress-strain curve, and energy absorption capacity will be used to measure the performance of the structure under different loading conditions. The new structure is designed to withstand maximum loadings before failure and must not exhibit premature failure within the walls of the unit cells. Design for Additive Manufacturing (DfAM) is being used to improve the printing quality of the auxetic core of the panel. Infill density and infill pattern can be optimized to reduce weight without compromising mechanical strength. Layer thickness can also be optimized to control printing time, weight, and certain mechanical parameters. The additively manufactured panel will be tested under compression, bending, and impact loadings using Split-Hopkinson pressure bars and digital image correlation techniques.