Theoretical Study On Partial-stability Of Foam-filled Thin-walled Hulls

The problem of partial-stability for foam-filled thin-walled hulls are intensively investigated in need of enhancing the anti-sinking capability of the ribbon floating bridge. Partial-stability problem of the hollow hull, frame-support hull without or with ribs is studied theoretically and numerically in a systematic way. The main work and result are as follows:(1)FEM models of hollow hull and frame-support hull without ribs are established, which are analyzed by ANSYS. The hull's elastic buckling loads and buckling modes are obtained under the vertical bending condition. The results show that the elastic buckling of the hulls are controlled by top-plate, and the frame-support can enhance the hull's stability.(2) FEM model of frame-support hull with ribs is established, which is analyzed by ANSYS. The hull's elastic buckling loads and buckling modes are obtained under the vertical bending condition. The results show that the elastic buckling of the hull is controlled by the smaller cases of top plate, and the reinforcing ribs are able to enhance the hull's stability.(3)Basic structure of the foam-filled hull is selected out by FEM analysis, and the FEM model of the foam-filled hull is established, which is analyzed by ANSYS. The hull's elastic buckling load and buckling mode are obtained under the vertical bending condition. The results show that the foam filled in the hull can enhance stability, and the buckling loads as well as buckling modes are influenced by the foam. Under the condition of equal weight, the already-existing hull's partial stability performance can be matched by the foam-filled hull.(4)Based on the results of FEM analysis and practical application, the simplified model for analyzing the problem of partial-stability of the hulls is presented. Rectangle plate on elastic support with rotation-restraint along unloaded edges is analyzed. Effects of rotation-restraint, elastic support and aspect ration of the plate on the buckling modes and buckling loads are studied, and the applicable range of the presented model and practical calculating method for partial stability analysis of the hull are developed.