Reliability and Remaining Life Assessment of Fatigue Critical Steel Structures: Integration of Inspection and Monitoring Information

摘要

The accurate prediction of the time-dependent damage level under uncertainty is an essential task in the management of fatigue critical steel structures. Structural health monitoring (SHM) and inspection actions can greatly improve the reliability of the prediction process. This is partly achieved by reducing the uncertainties associated with load estimates and actual structural responses. Additionally, SHM and inspections provide a deeper insight into the damage level at the time of application of such actions. This paper proposes a probabilistic approach for quantifying the reliability and the remaining service life of fatigue deteriorating steel bridges based on the information form SHM and inspection actions. The approach utilizes a probabilistic crack growth model which considers uncertainties associated with the damage propagation process and monitoring outcomes to find the remaining fatigue life and predict the lifetime reliability of the analyzed location. Future inspection actions are scheduled based on the predicted lifetime performance profiles. An updating process is employed to find the posterior model parameters based on the damage level quantified during inspections. Updated damage propagation and lifetime reliability profiles are established. The proposed method can support the decision making process and the life-cycle management under uncertainty. An existing fatigue critical detail of a steel bridge is used to illustrate the proposed approach.