This article proposes a method for assessing fatigue damage in reinforced concrete bridges based on a train-bridge coupled dynamic analysis system. The analysis system can be used to perform coupled vibration analyses of the bridge’s behavior during train passages. The Palmgren–Miner rule is used to estimate the linear accumulation of fatigue damage based on recommended S–N relationships for reinforced concrete from various codes. The method can be used to evaluate the dynamic performance of a bridge in conjunction with moving load (ML) and moving spring-mass-damper (MSMD) vehicle models. Calculated dynamic stresses are used to evaluate the fatigue damage at critical locations. A case study is presented focusing on the Långforsen Bridge, a railway arch bridge with a span of 89 m in northern Sweden. Fatigue assessments are conducted by combining the presented method with empirical measurements, and the effects of train speed and axle load on fatigue damage are investigated. Train-bridge coupled dynamic analysis using the proposed method provides a feasibly accurate solution for fatigue damage prediction in the four studied load cases. For low speeds and light loads, the two vehicle models yielded identical predictions of cumulative fatigue damage. However, their predictions diverged significantly for higher speeds and/or axle loads.

本文提出了一种基于钢桥耦合动力分析系统的钢筋混凝土桥梁疲劳损伤评估方法。该分析系统可用于对列车通过过程中桥梁行为进行耦合振动分析。根据建议的S – N，使用Palmgren–Miner规则估算疲劳损伤的线性累积不同规范中钢筋混凝土的关系。该方法可用于结合移动负载（ML）和移动弹簧质量阻尼器（MSMD）车辆模型评估桥梁的动态性能。计算出的动态应力用于评估关键位置的疲劳损伤。本文以瑞典北部Långforsen桥为例，这是一座跨度为89 m的铁路拱桥。通过将提出的方法与经验测量相结合进行疲劳评估，并研究了列车速度和轴载荷对疲劳损伤的影响。使用所提出的方法进行的车桥耦合动力分析为四个研究载荷情况下的疲劳损伤预测提供了可行的准确解决方案。对于低速和轻载，两种车辆模型对累积疲劳损伤的预测相同。但是，对于更高的速度和/或轴负载，他们的预测大相径庭。