温度作用对带铺装层钢桥面板疲劳效应的影响研究

以润扬大桥悬索桥为考察对象,基于实测结果研究了铺装层温度变化对钢桥面板两类焊接细节疲劳效应的影响特征。由于润扬大桥悬索桥疲劳分析模型计算单元数多且耗时大,首先利用模型参数敏感度分析方法确定钢桥面板疲劳效应简化分析模型中的敏感参数,然后利用敏感系数矩阵迭代法计算各个敏感参数的最优取值。在此基础上建立了带铺装层钢桥面板的疲劳效应简化分析模型,并考察了不同温度作用下两类典型焊接细节的疲劳效应。分析结果表明:1)两类焊接细节的日等效应力幅与钢桥面板温度存在较强的线性相关性;2)钢桥面板疲劳效应的简化分析模型为顺桥向支承在横隔板上、横桥向支承在顶板纵肋上的局部受力结构体系;3)带铺装层钢桥面板的疲劳分析方法能够准确计算车辆荷载和温度共同作用下焊接细节的疲劳效应。

Influence of temperature action on the fatigue effect of steel deck with pavement

With regard to the steel deck of Runyang Suspension Bridge, the influences of temperature changes of pavement on the fatigue effects of two types of welded details are investigated based on monitoring data. Because of large amount of elements in the global finite element model of Runyang Suspension Bridge, the sensitive parameters of a simplified finite element model for the fatigue analysis of the steel deck is firstly obtained based on the sensitivity analysis, and then the optimal values of sensitive parameters are calculated by the matrix iteration of sensitive coefficients. Furthermore, the simplified finite element model for the fatigue analysis of the steel deck with pavement is established and the fatigue effects of two typical welding details under changing temperature actions are investigated. The analysis results reveal that:1) the equivalent stress amplitudes of two types of welded details are linearly correlated with the temperature of a steel deck;2) the simplified analytical model for the fatigue effects of the steel deck is a partially structural system, which is longitudinally supported on the transverse diaphragm and transversely supported on the longitudinal rib;3) the analytical method for the fatigue effects of a steel deck with pavement can accurately calculate the fatigue effects of welded details under the combined actions of vehicle loading and temperature.