Reliability analysis of fatigue under random loading considering modeling updating through inspection in the MARTA bridge system

摘要

Plan for the fatigue damage evaluation of the full-penetration butt welds bridges requires the development of reliability-based analysis, inspection and maintenance procedure. To account for the uncertainties in the material properties and environmental conditions, a stochastic fatigue crack growth model is proposed here. Recent calculations using the Monte-Carlo Simulation technique shows that the first-order reliability method gives very accurate result. The sensitivity and capability of ultrasonic inspection are investigated in this study. The reliability of inspections for various events is formulated. Efficient algorithms for updating the reliability model through inspection are proposed. A case study is conducted for MARTRA's steel bridges system. Analysis of results includes fatigue reliability index, inspection, repair, updating of random variables and inspection plan. Results indicate the proposed model gives an accurate and practical approach to the fatigue control in the steel structures.