江阴长江大桥钢箱梁疲劳应力监测及寿命分析

Fatigue Stress Monitoring and Fatigue Life Analysis of Steel Box Girder of Jiangyin Suspension Bridge

针对江阴长江大桥钢箱梁,进行了疲劳应力的监测分析和疲劳寿命的预测研究。利用实桥布设的应变传感器获取应变时程数据,处理成应力时程数据并结合雨流计数法技术,得到"日应力谱"和"标准日应力谱"。根据相关疲劳规范,研究了钢箱梁的疲劳寿命等问题。结果表明,由于车辆荷载谱或有限元模型均存在大量的假定简化,利用记录的应变(应力)时程数据进行疲劳寿命评估,为准确可靠的研究方法;应变传感器记录分析得到的日应力谱具有相似规律,"标准日应力谱"方法可以有效地处理应变传感器记录的大量实测数据。

For steel box girder of Jiangyin Suspension Bridge, fatigue stress monitoring and fatigue life prediction were implemented. Monitoring data of strain-time were obtained by using the strain transducer distributed on the Jiangyin Suspension Bridge. After the monitoring data of stress-time were calculated from the monitoring data of strain-time, ＂day stress spectrum＂ and ＂standard day stress spectrum＂ were obtained with help of the rain flow count method. Based on the related fatigue criterion, fatigue life prediction of steel box girder was discussed. The result shows that （1） utilizing the recorded data of stress-time （strain-time） to estimate the fatigue life of the actual bridge is an accurate and reliable method due to the supposition and simplification of vehicle load spectnnn and finite element model; （2） different day stress spectra from the monitoring data of the strain transducer have similar characteristics and the method of ＂standard day stress spectrum＂ adopted in this paper can tackle the huge amount of measured data efficiently.