| Compared with traditional metal materials, fiber-reinforced composite (FRC) has designable mechanical properties,higher strength and stiffness ratio. Thus FRC is widely applied in ship industry. Delamination is one of the most frequently encountered failure mode in structures of composites which will decrease the strength and stiffness. With the extensive application of composite materials in ship industry and the tendency that the size of ship hulls in composite materials is upon large-scale and super large-scale, it is urgent and necessary to study the overall structural performance of composite ships and delamination damage. Based on special properties and characteristics of composite materials, comprehensive study of numerical analysis for overall structural performance of composite ships and delamination damage is conducted.Based on model of equivalent stiffness of laminates, laminates of composite ship hull, simplified as orthotropic lamina, are modeled using degenerated shell elements based on first-order shear deformation theory. Adjustment of stiffness of equivalent lamina and refine net are used to reflect mechanical properties of local reinforcement of laps. Results of numerical analysis of mode, stiffness and local stress under different load conditions have been compared with the experimental results,suggesting that the method for finite element modeling of composite ship hull meets engineering precision and consumes less working load.Based on the first-order shear deformation theory and fracture mechanics theory, two-dimensional finite element model is established to predict crack propagation. The energy release rate (ERR) is solved by the virtual crack closure technique (VCCT), using the total energy release rate as crack propagation criterion. The post-buckling response and growth of circular delamination in flat plates are investigated, and results are compared well with the experimental results. |
