Fatigue Damage Estimation Method of Steel Highway Bridges

Due to the increasing traffic volumes, heavy loaded trucks and use of high strength materials, fatigue problems are reported as main causes of structural failures of steel highway bridges. However, the fatigue design procedure in current practice is so crude to consider the variety of traffic patterns, such as vehicle types, weights, etc. In this study, for the purpose of development of rational fatigue damage estimation method, the impact coefficient model has been proposed. The traffic flow models are also developed, which can be applied to any traffic patterns. The sensitivity analysis on cumulative fatigue damage has been performed to evaluate the effect of important parameters, such as average daily truck traffic volume (ADTT), average daily traffic volume (ADT), characteristic of consecutive vehicle type, impact coefficient, etc.