Journals Proceedings

Abstract

A dynamic analysis of axially loaded Timoshenko beams with intermediate fixities is presented. The underwater part of a craft is modeled as a flexible beam, which rises out and slams against the water at a large vertical velocity, causing highly localized hydrodynamic impact pressure moving at high velocities across the beam, setting it into high-frequency vibrations. The beam natural frequencies depend on the slenderness ratio, axial load, and end fixities. Increasing the axial tension and/or end fixity increases the natural frequencies, which are generated through Eigen analysis. Next, normal mode summation is used to analyze the impact-induced vibration response, which is generated for various impact speeds, deadrise angles, end fixities, axial loads, and slenderness ratios of the beam. A parametric study is done to predict the maximum dynamic stresses on the structure. The pressure is assumed to act at the equilibrium position. The aim is to study the dynamic stress configurations and draw conclusions leading to sound structural designs.