Ultimate Strength Analysis For Ship Hull's Bulkhead Structures

In the past decades, the loss of vessels is serious. The recent study has found that in the case of ship sinkage, the bulkheads are vital structures in the situation. There is a possibility that the collapse of bulkheads and subsequent progressive flooding may have been a cause in some of recent ship losses. Numerous losses show that the design of bulkhead is defective or the strength storage of bulkheads is inadequate. Therefore, it is necessary to do strength and stability analysis for bulkhead structures, in order to find out the influence of bulkhead parameters on the strength and stability of bulkhead, and then provide beneficial reference for the design of bulkheads.After summarizing the results of former researchers, the thesis uses theoretical analysis and FEM to do strength and stability calculation for bulkhead structures, the main content is as follows:1. Analyze lateral stability of bulkhead stiffeners under lateral hydrostatic pressure, and the critical load formula of stiffeners have derived by energy method in the thesis. The formula is used to calculate the critical load of stiffeners of different length or different web thickness, and to find out the influence of length and web thickness on the critical load.2. FEM is also used to calculate the critical load of bulkhead stiffeners under lateral hydrostatic pressure, and then the result is compared with that calculated by the formula. The results are approximated to each other, which proves that the formula is correct and practical.3. Analyze the structure styles, load and boundary conditions of corrugated bulkheads, then calculate the bending moment of a singe corrugated beam under linear pressure, as well as the critical pressure with several idealized boundary conditions. By calculate we can find that boundary conditions have a lot to do with the critical pressure.4. Optimize the size of corrugated bulkheads by FEM to improve the strength and of corrugated bulkheads and also to reduce costing. Under the precondition of meeting rules' provision, bulkheads are designed to have more strength in the same costing, or with less costing within the permitted strength range.