An Accurate Life Estimation Method for Existing Railway Bridges

The paper proposes an accurate methodology to estimate remaining fatigue lives of riveted railway bridges. The proposed method mainly consists of measured stress histories, recently developed sequential law and fully known Wohler curve. Here, it is essential to use the fully known Wohler curve as the related fatigue curve. Therefore the technique, which utilizes to transfer the partially known Wohler curve to fully known curve, is also discussed under this paper. Since most of the bridges do not have past strain measurements, this method describes reasonably accurate procedure to obtain the past stress histories from present day measured stress histograms. Initially paper describes the proposed method for remaining fatigue life estimation. Secondly remaining fatigue life of an existing railway bridge is estimated by performing a case study. Case study describes the details of the considered railway bridge and the appraisals related to condition evaluation, FE analysis, material testing, experimental static and dynamic load testing. Then the remaining fatigue lives of each critical components of the bridge are obtained. Hence validity and merits of proposed method is confirmed by comparing the results with previous method-based fatigue lives.