Application of Structural Reliability Approach to Assist Hull Integrity Management

摘要

There is a growing interest within the industry on developing practical methods that can be used to improve hull (structural) integrity management (HIM) of ships. There is a pressing need for engineering tools that can reasonably predict the future structural condition of a vessel, taking into account the various uncertainties that can influence the degradation of the structure over the life of a ship. The structural reliability approach (SRA) provides a promising tool that, once established, is capable of assisting a ship owner or operator in making rational decisions with respect to when, where and how to conduct inspections and implement a more effective maintenance strategy. To be effective within a through-life HIM program, the SRA tools need to be rationally based and easy to use. They should focus on the three principal elements subject to potential failure - the hull girder (strength), the panels (buckling and yielding) and structural connections under cyclic load (fatigue). The uncertainties that should be considered include the vessel's trading environment, loads, structural responses, material performance, structural degradation, inspection, maintenance and repairs. The following issues should be addressed when the SRA is introduced to rationalize the practice of HIM: • Requirements of inspection, maintenance and repair • Idealization of these requirements as mechanical models • Definition of uncertainties • Solution of SRA problems • Selection of acceptance criteria • Decisions about when, where and how to conduct inspections, and whether to make repairs or take other remedial actions. To date, technical publications and investigative analyses have tended to be grouped in accordance with these aspects. The paper will describe the potential direction for rationalizing HIM practice, review the current state of the art of SRA, and discuss the gaps in current technological approaches.