Dynamic Response of Local Hull Structures Under Moving Slamming Loads

Abstract

The bow of a ship is often subjected to the action of moving slamming loads, and the slamming phenomenon occurs frequently, which has significant effect on the local and global structural response. In this paper, Euler-Bernoulli beam theory and modal superposition method are adopted to study the dynamic response of a beam under the moving slamming load. The slamming pressure is characterized as pulse load that moving along the longitudinal direction at a constant speed. The problem is solved using a Fourier sine integral transformation in space and a Laplace-Carson integral transformation in time. Deflection and stress as functions of time and position for different speeds, bending stiffnesses, etc. are given. The cases that arrival of a pulse load on a beam, steady-state vibration, departure of a pulse load from a beam all have been considerated in theoretical model. Based on the proposed theoretical model, the influence of parameters such as load rising section coefficient, migration velocity on the dynamic response of beams under moving slamming load is studied and the associated results are compared with those using the finite element method. The proposed theoretical model is useful in understanding the slamming impact and evaluating the dynamic response of structural components under slamming loads.