Finite element analysis of cell size, porosity, and density effects on aluminum foam crash box performance

Abstract

Vehicle safety remains a critical aspect of automotive design, with a growing emphasis on developing advanced materials and structures that efficiently absorb impact energy during collisions. Closed-cell aluminum foam-filled sandwich crash boxes have emerged as a promising solution, offering both lightweight properties and enhanced crashworthiness. This study explores the modeling and optimization of such crash boxes using Digimat-FE and Finite Element Analysis (FEA), focusing on key parameters such as cell size, porosity, and density to maximize energy absorption. A series of simulations was conducted to evaluate the energy absorption capabilities of closed-cell aluminum foam in various configurations. The results show that smaller cell sizes (10 mm) and lower void fractions (0.15) yield the highest energy absorption, reaching up to 255 J. Furthermore, FEA simulations reveal that integrating aluminum foam into sandwich structures significantly improves the crash box's ability to absorb energy, compared to traditional empty aluminum alloy crash boxes. This study highlights the potential of closed-cell aluminum foam in optimizing vehicle crashworthiness while maintaining lightweight and sustainable design principles.