An analytical approximation of focusing-wave-induced load on a semi-submerged cylinder

Owing to the complexity of the physical mechanisms of rouge waves,the theoretical study of the rogue-wavestructure interaction problems still makes little progress.However,for regular-shaped structures,it is possible to give a theoretical analysis,if a relatively simple model of the rogue waves is used.The wave load,induced by a focusing wave which is known as an intuitive basic model of the rouge waves,upon a semi-submerged cylinder is studied analytically.The focusing wave is approximate by the Gauss envelope wave,an ideal model which contains most features of the rogue wave.The diffraction velocity potential is derived through the separation of flow field,and the formulas of the horizontal force and bending moment are proposed.The derived formulas are simplified appropriately,and validated through comparison against numerical results.In addition,the influence of parameters,such as the focusing degree,the submerging depth and the wave focusing position,is thoroughly investigated.