A Universal Performance-Based Rating System for Existing Structures via Fuzzy Logic: A General Framework

The performance rating of an existing structure is critical in planning proper maintenance actions. Visual inspection is often used to assess the condition of existing structures because of its efficiency when assessing a large inventory of structures. Visual inspection is challenged by a high degree of uncertainty in the evaluation results and subjectivity in the method of assessment. In this study, Fuzzy logic is used to develop a novel universal performance-based rating (UPR) system to rate the performance of structures based on visual inspection data, considering uncertainties in site evaluations. The framework comprises of five main steps: (1) defining the performance criteria of the structure under assessment, (2) defining the material deterioration models, (3) using fuzzy logic principles to map the observed damage states into numerical values of material properties, (4) conducting fuzzy-numerical analysis to evaluate performance, and (5) drawing performance charts as the primary goal of the proposed technique. With the aid of these performance charts, inspectors can make more reliable decisions regarding the condition of the damaged structure, which ultimately leads to a better budget distribution for infrastructure maintenance from a more general perspective. For demonstration, a UPR system is developed to assess a simply supported beam based on visual inspection.