Analysis Reliability Of Imperfect Ship Structure

During the process of structural analysis and design, we usually neglect the influence of all kind of actual working condition on structure system reliability . For actual structure, however, it is inevitable that initial error fabrication and occasional accident may produce any kind of structure initial imperfection and then the structure become a imperfect structure. At present, the research, which based on imperfect structure reliability ,is in initial stage. This paper attempt to study soma problem about those aspects. The main contents of this paper are as follow:1. A improved response surface method with the vector projection technique is proposed in this paper, the method is proved to be a more quick and more effective method for structure reliability analyses.2. For imperfect strut, there exists bending deformation from the beginning of structure loading because of the initial geometric imperfection and the initial eccentric loading imperfection. For this reason, Eulor critical load is no longer applicable to duilding of the safe margin equation. This paper defines the risk design section at the out-edge deflection mid-point of compressing struct to build its safe margin using non-ideal struct strength theory and calculate the reliability of imperfect strut.3. Reliability analysis of ultimate strength of plates with initial impact. In this paper, three kinds of imperfect structure are considered, which are initial deflection, local dent, fatigue cracking damage, on ship plate. Considering the initial deflection and the residual stress and resting on the related ultimate strength...