FATIGUE LIFE PREDICTION OF RAILWAY BRIDGE |
Author(s): |
Pushpak Bankapalli |
Keywords: |
Abstract |
With mechanical failures growing day by day due to fatigue and brittle fracture, in various systems related to different spheres of engineering and technology, it is high time when low cost and effective methods should be adopted to determine life of existent structures and also design new ones more effectively. It is seen that repeated loads which are variable in nature cause damage five times more than the static loads. Generally members acting in tension and flexure, joints, etc are among the first ones tofail. In India there are about 250 important and 3000 major bridges older than 100 years and 180 important and 2900 major bridges aging 50-100 years. Steel bridges are reaching or have exceeded their original design life. These structures have experienced increasing traffic volume and weight, deteriorating components as well as a large number of stress cycles. Therefore, evaluation of remaining fatigue life for their continuing service has become necessary, especially for decisions on structure replacement, deck replacement, or other majorretrofits. In the present study parametric study on four case studies is done. In the first parametric study only the material degradation is considered keeping the traffic volume same, the damage occurring in the most stressed member of the bridges is calculated. While in the second parametric study material degradation as well as increase in traffic volume is considered. Maximum increase in damage in comparison with first study occurs in 45.7 m Truss Bridge with the increase in traffic volume. Prediction of remaining fatigue life is done for two cases namely, bridge history known and bridge history unknown. In the history known case, remaining fatigue life is calculated for 45.7 m Truss Bridge. While in history unknown case the past traffic volume and material properties are not known. To know the material properties experiments are done to derive S-N curve for the bridge material coupons. |
Other Details |
Paper ID: IJSARTV Published in: Volume : 7, Issue : 3 Publication Date: 3/2/2021 |
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