On impact loading of Voronoi functional graded porous structure

Abstract

In the realm of developing novel lightweight forms with enhanced mechanical properties, structural innovation introduces a fresh perspective, with a key focus on porous structures that must be addressed. Different from previous gradient control methods, this paper focuses on porosity (relative density) control criteria and establishes porous structures with different porosity gradients. This paper aims to evaluate the potential application of Voronoi functional graded porous structures (FGPS). The study employs Poisson-Voronoi tessellation to generate FGPS models, creating four Voronoi porous structures with diverse porosity gradients. Model verification involves comparing results with the Gibson-Ashby porous structure theory. Subsequent analyses rely on numerical modeling and finite element analysis (FEA) using Abaqus. The research explores the impact of varying impact velocities and directions as parameters for analysis. Parametric studies reveal that the most influential factor affecting the deformation behavior of Voronoi FGPS is the impact velocity. As impact velocity increases, the influence of gradient magnitude and direction becomes relatively less pronounced. Notably, the stress-strain relationship on the impact side shows greater sensitivity to impact velocity compared to the fixed end. Furthermore, the energy absorption of Voronoi FGPS demonstrates varying advantageous ranges under different operational conditions, including impact velocity and final strain levels. In summary, the size, direction, and impact velocity of the porosity gradient in Voronoi FGPS distinctly influence deformation behavior, stress-strain relationships, densification strain, plateau stress, and energy absorption at different strain levels. The future of FGPS lies in the development of advanced materials with increasingly sophisticated gradients, allowing for superior performance optimization in demanding applications, such as the lightweight and crashworthiness design of vehicles and aircrafts, biomimetic porosity designs and protective layers for civil engineering. These findings provide valuable insights for the practical design of porosity-controlled FGPS.