Comparison of Two Different Hold Frame Structures of a Bulk Carrier Based on Structural Reliability Analysis

摘要

Recently, risk-based design of ship structures becomes very important concept in order to ensure the lifecycle safety of ship structures. In this paper, we carried out structural reliability analysis for two different designs of the hold frame structure of a bulk carrier, and compare them by examining the risk and the cost-benefit analysis. For evaluation of structural failure of aging ships, it is necessary to consider structural deterioration such as corrosion. It is known that corrosion wastage is much severer near the welded area of the intersection between the web plate and the shell plate, which is called as grooving corrosion. In this study, structural reliability analysis is carried out using both a uniform corrosion model and a grooving corrosion model. It is found that the failure probability considering the grooving corrosion is higher than that without the grooving corrosion. Moreover, even though one structure is evaluated as better than the other structure from the viewpoint of lifecycle benefit when only uniform corrosion is considered, the contrary result may happen if the grooving corrosion is considered in the corrosion wastage model.