Numerical and experimental study of a crash absorption keel

Aim of this paper is to study the impact between the sailing boat keel and the ground and to look for the optimal configuration of the bulb-keel-hull system able to direct the damage in the bulb-keel zone avoiding the hull region. The research, which is carried out in collaboration. with Wally shipyard, requires firstly an accurate investigation of the bulb-keel-hull system geometry, of the boat inertial properties and of the impact condition. Secondly, a numerical dynamic analysis by means of the finite element method allows to model the impact and to determine how, during the collision, the state of stress varies and how the kinetic energy is absorbed/dissipated. Starting from these results, the performance of the present configuration is evaluated in several conditions and some proposals for new design configuration are made. In particular the results carried out from the new design analyses were evaluated comparing themselves to results obtained from experimental studies.