EXPERIMENTAL RESEARCH OF CHARACTERISTICS OF RIGID POLYURETHANE FOAM FOR KINETIC COLLISION ABSORPTION SYSTEMS – OGDEN MATERIAL MODEL

Abstract

Rigid polyurethane (PU) foam was investigated as a filling material for a tube collision energy-absorbing component intended for railway vehicle crashworthiness applications. Quasi-static uniaxial compression tests were performed on cubic specimens extracted from a cylindrical PU foam block with a nominal density of 175 kg/m³ in order to characterize its compressive behavior and obtain material parameters for finite element analysis (FEA). The experimental stress–strain curves exhibited the characteristic nonlinear response of cellular material. An Ogden foam constitutive model was subsequently calibrated in Ansys using experimental compression data and implemented in numerical simulations of energy absorber designs. The numerical study evaluated the force–displacement behavior and energy absorption capability of each configuration under quasi-static axial compression applied through a conical bushing. For a compression stroke of 60 mm, the fully foam-filled tube demonstrated a 16% increase in absorbed energy compared with the empty tube, while the configuration incorporating the concentric steel core achieved an improvement of 9.5%. The findings confirm that the incorporation of rigid PU foam enhances the quasi-static energy absorption performance of tubular railway crash absorbers.