The design of hydraulic steel gates subject to wave motion and fatigue life prediction according to the theory of stochastic dynamic analysis

Abstract

Linear wave theory is used to give a design procedure for a steel gate. For designing the steel gate, the wave pressure spectrum is adapted from the Pierson-Moskowitz wave height spectrum, and then a stochastic dynamic analysis is performed. After calculating the stress analysis for the steel gate, the fatigue life is predicted. The steel gates in a habor are subject to hydrostatic pressures and the dynamical forces of the wave motions. In design, the maximum stresses developed in the steel gates from hydrostatic pressures and dynamical forces of the wave motions must be equal to or less than the allowable stresses. On the other hand, the wave motions cause variable-amplitude random-sequence stresses in the gates. An analytical method is given for the prediction of the fatigue life of the steel structures under variable-amplitude random-sequence stress spectrum from constant amplitude fatigue stresses.