Impact-induced flexural response of axially loaded uniform Timoshenko beams with non-classical ends: a sensitivity study of the dynamic load factor

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, end fixities, and structural damping. The natural frequencies and modeshapes (for total deflection and pure bending slope) 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, and axial loads, of the beam. A parametric study is done to predict the maximum dynamic stresses on the structure. The sensitivity of the dynamic load factor (DLF) is studied with respect to the above parameter space. Conclusions are drawn leading to insights into sound structural designs.