中文3040字出处：Ocean engineering, 2007, 34(11): 1516-1531外文Hydroelastic analysis of flexible floating interconnected structuresThree-dimensional hydroelasticity theory is used to predict the hydroelastic response of flexible floating interconnected structures. The theory is extended to take into account hinge rigid modes, which are calculated from a numerical analysis of the structure based on the finite element method. The modules and connectors are all considered to be flexible, with variable translational and rotational connector stiffness. As a special case, the response of a two-module interconnected structure with very high connector stiffness is found to compare well to experimental results for an otherwise equivalent continuous structure. This model is used to study the general characteristics of hydroelastic response in flexible floating interconnected structures, including their displacement and bending moments under various conditions. The effects of connector and module stiffness on the hydroelastic response are also studied, to provide information regarding the optimal design of such structures.Very large floating structures (VLFS) can be used for a variety of purposes, such as airports, bridges, storage facilities, emergency bases, and terminals. A key feature of these flexible structures is the coupling between their deformation and the fluid field. A variety of VLFS hull designs have emerged, including monolithic hulls, semisubmersible hulls, and hulls composed of many interconnected flexible modules.Various theories have been developed in order to predict the hydroelastic response of continuous flexible structures. For simple spatial models such as beams and plates, one-, two- and three-dimensional hydroelasticity theories have been developed. Many variations of these theories have been adopted using both analytical formulations (Sahoo et al., 2000; Sun et al., 2002; Ohkusu, 1998) and numerical methods (Wu et al., 1995; Kim and Ertekin, 1998; Ertekin and Kim, 1999; Eatock Taylor and Ohkusu, 2000; Eatock Taylor, 2003; Cui et al., 2007). Specific hydrodynamic formulations based on the modal representation of structural behaviour, traditional three-dimensional seakeeping theory, and linear potential theory have been developed to predict the response of both beam-like structures (Bishop and Price, 1979) and those of arbitrary shape (Wu, 1984), through application of two-dimensional strip theory and the three-dimensional Greens function method, respectively. Other hydroelastic formulations also exist based upon two-dimensional (Wu and Moan, 1996; Xia et al., 1998) and three-dimensional nonlinear theory (Chen et al., 2003a). Finally, several hybrid methods ofhydroelastic analysis for the single module problem have also been developed (Hamamoto, 1998; Seto and Ochi, 1998; Kashiwagi, 1998; Hermans, 1998). To predict the hydroelastic response of interconnected multi-module structures, multi-body hydrodynamic interaction theory is usually adopted. In this theory, both modules and connectors may be modelled as either rigid or flexible. There are, therefore, four types of model: Rigid Module and Rigid Connector (RMRC), Rigid Module and Flexible Connector (RMFC), Flexible Module and Rigid Connector (FMRC) and Flexible Module and Flexible Connector (FMFC). By adopting two-dimensional linear strip theory, ignoring the hydrodynamic interaction between modules, and using a simplified beam model with varying shear and flexural rigidities, Che et al. (1992) analysed the hydroelastic response of a 5-module VLFS. Che et al. (1994) later extended this theory by representing the structure with a three-dimensional finite element model rather than as a beam. Various three-dimensional methods (in both hydrodynamics and structural analysis) have been developed using source distribution methods to analyse RMFC models (Wang et al., 1991; Riggs and Ertekin,1993; Riggs et al., 1999; Cui et al., 2007). These formulations account for the hydrodynamic interactions between each module by considering the radiation conditions corresponding to the motion of each module in one of its six rigid modes, while keeping the other modules fixed. By employing the composite singularity distribution method and three-dimensional hydroelasticity theory, Wu et al. (1993) analysed the hydroelastic response of a 5-module VLFS with FMFC. Riggs et al. (2000) compared the wave-induced response of an interconnected VLFS under the RMFC and FMFC (FEA) models.They found that the effect of module elasticity in the FMFC model could be reproduced in a RMFC model by changing the stiffness of the RMFC connectors to match the natural frequencies and mode shapes of the two models.The methods considered so far deal with modules joined by connectors at both deck and bottom levels, so that there is no hinge modes existed, or all the modules are considered to be rigid. In a structure composed of serially and longitudinally connected barges, Newman