Energy-absorbing aluminum composites for protecting concrete superstructures against over-height collisions

Abstract

Over-height collisions commonly pose the risk of structural damage, causing safety and functionality concerns. To prevent potential damage, various strategies have been attempted to date with limited success. Among possible strategies, the current study investigated the unique capabilities of energy-absorbing aluminum composites in providing a protective panel to resist impact-induced forces. To achieve a holistic assessment, three core alternatives, i.e., aluminum honeycomb, aluminum foam, and expanded polystyrene foam, sandwiched between aluminum plates, were considered in this study. The selected composite panels had been used as impact-resistant components in mechanical and aerospace engineering applications, but their applications in the civil engineering domain had remained marginal, mainly because of limited studies performed on them. To address the fundamental questions related to the response of this category of composites to over-height collisions, the current study utilized a set of high-fidelity finite-element models. The developed models were validated with a suite of experimental test results from past studies. The models replicated two representative concrete girders, each without and with energy-absorbing composite panels. The added panels were in various configurations, in terms of geometric and material properties. Upon simulating the over-height collision with a range of impact intensities and velocities, key response measures were evaluated, including energy absorption, impact force, and girder damage. This holistic investigation’s outcome led to a set of recommendations on the energy-absorbing composites of choice configured to minimize the damage from over-height collisions.