Evaluating elastic modulus and energy absorption efficiency of composite metal foam using computational and experimental approaches

Abstract

This study evaluates the mechanical performance of steel composite metal foams (CMFs) under various temperatures to assess their potential for use in thermally demanding environments. Steel CMFs, composed of hollow steel spheres embedded in a stainless steel matrix, were subjected to quasi-static compression tests at 23 °C, 400 °C, 600 °C, 700 °C, and 800 °C. The primary objectives were to assess the temperature-dependent changes in elastic modulus, plateau strength, energy absorption efficiency, and structural integrity under compression. Experimental results revealed characteristic stress–strain behavior comprising linear elastic, plateau, and densification regions, with significant mechanical degradation observed at temperatures beyond 600 °C. To account for the volumetric changes in steel CMF, a correction factor (K) related to porosity (ϕ) was introduced, relating true and engineering stress. Curve fitting at room temperature yielded K = 0.6, closely matching the CMF porosity (ϕ = 0.6), highlighting porosity’s dual physical and mathematical significance in governing the compressive response of CMFs. Finite element simulations in ABAQUS were used to complement experimental findings, incorporating a crushable foam plasticity model and temperature-dependent material properties. The model accurately predicted the mechanical behavior of steel CMF up to the densification phase, with discrepancies remaining below 4% compared to experimental results. Computational analysis also validated the assumption of a constant Poisson’s ratio at elevated temperatures. Results indicate that steel CMFs maintain substantial energy absorption and mechanical stability up to 600 °C, making them suitable for applications such as crash absorbers and thermal shields. However, performance deteriorates significantly at 700 °C and 800 °C due to thermal softening and oxidation, ultimately leading to structural disintegration. This study underscores the promise of steel CMFs in thermally demanding applications while identifying key areas for future research, including the refinement of computational damage models and the experimental validation of temperature-dependent material parameters.