The hydroelastic response analysis of large floating structures is formulated by a wet-mode superposition approach. The floating structure is discretized by fmite elements (FE), whereas fluid domain by boundary elements (BE). Structural analysis is based on the Mindlin's plate theory. Only the structure-fluid interface is discretized in the fluid domain. The equation of motion is constructed by coupling BE and FE on the fluid-structure interface. Quadratic isoparametric elements are used for both FE and BE. The accuracy and effectiveness of the BE-FE hybrid model and wet-mode approach are verified by comparing with published experimental results on the hydroelastic response of a rectangular floating structure for a wide variety of incident wavelengths and angles. Moreover, the hydroelastic response of floating structures with arbitrary shape is investigated to discuss on the local deformation of convex parts.
The hydroelastic response of large floating structures has been investigated by using either modal superposition or direct methods. The direct method is useful if extremely higher modes are dominated in the overall response (Yasuzawa et al., 1997, Ohmatsu, 1997; Nagata et al., 1997; Kashiwagi, 1998). The modal superposition method becomes efficient if the overall response is not so influenced by extremely higher modes. The modal superposition method is generally divided into drymode and wet-mode approaches (Bishop and Price, 1976; Ertekin et al.. 1995). So far, the dry -mode approach has been used more frequently for the hydroelastic response analysis of large floating structures than the wet-mode approach because of its simplicity and numerical efficiency (Takaki and Gu, 1996; Wu et al., 1997). Very few studies have been carried out by the wet-mode approach (Hamamoto et al., 1995, 1996, 1997). However, wet-mode properties are useful not only for the short-term response analysis but also for the long-term health monitoring.