摘要
为给钢桥面板焊接细节的设计及运营管理提供参考,针对随机车辆作用下的钢桥面板焊接细节,考虑交通量增长、车辆轴重的相关性和路表温度长期效应等因素的影响,进行了钢桥面板焊接细节的疲劳可靠度研究。基于某钢箱梁悬索桥WIM实测数据,分析了随机车辆各参数的分布特征,尤其是车辆轴重的相关性,采用能考虑轴重相关性的非参数核密度估计-Copula轴重抽样方法,编制了多参数随机车辆模拟程序;采用有限元法分析了路表温度、车辆轴重的相关性对疲劳荷载效应的影响;最后建立了基于疲劳损伤理论的功能函数,采用MC法进行疲劳可靠度计算,分析了交通量增长、轴重的相关性和路表温度长期效应对钢桥面板焊接细节疲劳可靠度的影响。研究结果表明:轴重具有多峰分布的特点,且轴重之间具有较强的相关性,模拟随机车辆时,如不考虑轴重的相关性,将会造成较大误差;路表温度变化主要影响钢桥面板焊接细节的应力幅,对循环次数和考虑车轮横向位置的应力幅折减系数影响不大,考虑路表温度长期效应的日等效应力幅,概率密度函数更具有多峰性质;考虑轴重相关性的日等效应力幅均值比不考虑轴重相关性的大;交通量增长对结构初期的疲劳可靠度指标影响不大,将造成结构后期的疲劳可靠度指标快速降低;考虑轴重相关性和路表温度长期效应均会降低钢桥面板焊接细节疲劳可靠度指标,而轴重相关性对疲劳可靠度指标的影响比路表温度长期效应更明显。
To provide a reference for the design and operation management of steel deck welding details,the fatigue reliability of steel bridge deck welding details was investigated in allusion to the steel deck welding under the action of random vehicle load.The influence of traffic growth,the correlation between axle load and long-term effects of pavement temperature were taken into the consideration.Based on WIM measured data of the steel box girder suspension bridge,the distribution characteristics of the random vehicle parameters,especially the correlation betweenvehicle axle loads,were analyzed.The random vehicle simulation with multi parameters was programmed by nonparametric kernel density estimation-Copula axle load sampling method,considering the correlation between axle loads.The influence of the pavement temperature and the correlation of the vehicle axle load on fatigue load effects was analyzed by dint of the finite element method.Finally,the function was established based on the fatigue damage theory.The fatigue reliability was calculated by MC method,and the influence of traffic growth,correlation of the axle load and long-term effect of pavement temperature on the fatigue reliability of steel deck welding details was analyzed.The results show that the axle load has the characteristics of multimodal distribution,and there is a strong correlation between axle loads. Without considering the correlation between axle loads,greater errors will be caused when simulating random vehicles.Pavement temperature changes mainly affect the stress amplitude of the steel deck welding details,with a little influence on the cycle numbers and the stress amplitude reduction coefficient in consideration of the transverse position of the wheel.Considering the long term effect of pavement temperature,the probability density function of daily equivalent stress amplitude presents multi peaks.The daily equivalent stress amplitude mean considering the correlation of axle load is much larger than that without taking the correlation bet
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2017年第11期89-98,共10页
China Journal of Highway and Transport
基金
国家重点基础研究发展计划("九七三"计划)项目(2015CB057701
2015CB057704
2015CB057705)
国家自然科学基金项目(51378081
51308071
51308073)
