Harbour resonance problems using finite elements

Abstract

The problem of harbour resonance is discussed, and the probabilistic analysis of a harbour's response is carried out using a finite element technique. The results presented in this paper show the importance of considering two types of damping (radiation and friction) in the study of harbour resonance phenomena. The radiation, or energy transfer between the harbour and the open sea, is introduced using an expression similar to Sommerfeld's radiation condition, and appears as a boundary only damping term. The three analyses with or without damping and with or without radiation are compared, and it is shown that it is important to include both effects to avoid distortion of the response spectrum. The probability of exceedance for elevations is calculated for the Duncan Basin, and a way of calculating the horizontal displacements is indicated.