Analysis Of Hydroelastic Responses Of Very Large Floating Structure By Use Of Sandwich Grillage Model.

It is particular when solve the hydrodynamic characteristic of the Very Large Floating Structure (VLFS). As the VLFS is a long, huge and thin flexible structure, it cannot be counted as a rigid body and its hydrodynamic response in waves is a typical problem of fluid-solid coupling. The hydroelastic theory can be carried for the qualitative analysis or the quantitative analysis with the load, motion, distortion and internal force in unification of the object which has random shape, and it represents the applicability in describing the problem of fluid-solid coupling. So, it is used widely in solving the VLFS. However, the mathematical models which used for calculating and analyzing with high-precision generally have extremely huge workload. In order to acquaint the logical characteristic of the hydroelastic response of the VLFS, a sandwich grillage model is introduced. With increasing a little calculation, the sandwich grillage model is more accurate than the homogeneous plate model.Based on the finite element soft, the sandwich grillage model is set up. By using Green Function method, the velocity potential is solved. The hydroelastic response function of the VLFS is founded and solved based on potential fluid theory.Introducing a calculating example, the sandwich grillage model and homogeneous plate model are used to calculate separately. Comparing the two calculation results, we can see that the trend of the two results is very similarly. Because the stiffness moment and the meshing are different between the sandwich grillage model and the homogeneous plate model, the two values have little difference. At last, in order to validate the method, another example is introduced. The result represents that the method can be used to estimate the deflection distortion of VLFS when the incident waves are oblique waves.