Stress Concentration Of Special Holes In Ship Girder And Their Reinforcements

The stress concentration phenomena occur in various structures. Up to now, engineers who show deep concern about the decrease of the stress concentration have developed several methods to solve this problem. They are analytical method, BEM, FEM and photoelastic trial method, and each has its special advantages and limitations.According to the fundamental theories of elastic mechanics and superposition principle, this paper presented a complex functional solution which is numerically effective for solving the stress concentration problem in an infinite two-dimensional elatromer with arbitrary shaped holes by introducing conformal mapping technique. Based on the above work, the author analyzed the stress in an infinite plate with oval hole which is commonly used in structures and figured curves of stress concentration to hole's shape parameters. By comparison of the corresponsive results of FEM, the author discussed those valid application areas of the method presented in this paper.In the second part, thinking of the fact that ship girders with special holes in web are commonly used, the author studied the stress concentration of this kind of structures by using FEM and discussed the influence of hole to overall structural strength and its reinforcing methods. After comparing the numerical results with photoelatic trial results, the author gives some advice on how to design structures with holes.