Vibration-induced Probabilistic Fatigue Life Assessment of a Suspension Bridge Carrying both Railway and Highway Traffic

摘要

In this paper, a fatigue reliability model integrated with stochastic stress concentration factor (SCF) is proposed based on the traditional S-N curve method in combination with the Miner's damage cumulative rule. Firstly, three probabilistic fatigue modelling methods, namely mean stress range method, integration method, and effective stress range method are briefed. Then, the proposed fatigue reliability model is formulated integrating with the probability distribution of hot spot stress range, and it is validated by conducting probabilistic fatigue life assessment of the suspension Tsing Ma Bridge (TMB) with use of the long-term strain measurement data from the structural health monitoring (SHM) system permanently installed on the bridge. Finally, the joint probability density function (PDF) of hot spot rainflow stress range as well as the failure probability and reliability index versus fatigue life are obtained.