Reliability-based design of doubler plates for ship structures

Maintenance, inspection, and repair are key aspects of managing the structural integrity of ship systems in a life cycle framework. For example, an inspection program can be developed with the objective of maintaining the structural integrity of a ship. It can start with system definition, followed by qualitative reliability assessment, and then quantitative reliability assessment with the objective of performing reliability-based design for maintaining system integrity. Doubler plates currently offer a temporary solution for plate damage in ship structures. The temporary nature of this fix stems from the lack of data on their performance and an engineering design guidance. We develop a reliability-based design model for an unstiffened panel with doubler plate(s) using both finite difference (FD) and finite element (FE) procedures. Partial safety factors were also determined to account for the uncertainties in strength and load effect. The first-order reliability method (FORM) was used to develop the partial safety factors.