DYNAMIC MODAL RESPONSES OF WAVE-EXCITED OFFSHORE STRUCTURES

Examinations are made of the dynamic effects associated with modal res ponses of deep-water, wave-excited offshore structures. Such examinati ons are intended to assess the influences that variations in several p arameters involved have on the dynamic structural response. Variations in the following parameters are considered: the distributions of the structural volume and projected area, the distributions of the inertia and drag force coefficients, the relative magnitude of the inertia an d drag force components, the natural modes of vibration of the structu re, and the random phase angles used for the generation of the wave lo ading. The response is examined for a wide range of values of the natu ral frequencies of the system, and the relative importance of the effe cts of changes in the parameters considered is elucidated. The results of the study provide valuable insight into the response of offshore s tructures to wave forces, and may contribute to forming a basis for th e development of future, efficient design procedures in the field of o ffshore engineering.