Design of a High Energy Absorbing Urethane Cylinder for Ship Fendering Systems

Abstract

A new design for a urethane cylinder is presented which exhibits very high energy absorption for a given maximum compressive force and for a given amount of urethane. These characteristics are obtained by altering the buckling response of the cylinder by casting in place equally spaced annular steel rings along the cylinder’s length and by introducing a small concave curvature to the cylinder’s walls. This geometry has been analyzed using nonlinear finite element analysis and confirmed with experiment for up to a 50 percent decrease in the cylinder’s original length. The comparison between theory and experiment is good.