随机车载下钢箱梁桥疲劳损伤概率模型  

Probabilistic Model of Fatigue Damage in Steel Box-girder Bridge Subject to Stochastic Vehicle Loads

作　　者：罗媛[1] 颜东煌[1] 鲁乃唯[2] 汪勤用 

机构地区：[1]长沙理工大学土木与建筑学院,湖南长沙410114 [2]东南大学土木工程学院,江苏南京210096

出　　处：《公路交通科技》2016年第10期81-87,共7页Journal of Highway and Transportation Research and Development

基　　金：国家重点基础研究发展计划(九七三计划)项目(2015CB057705);湖南省研究生科研创新项目(CX2015SS02)

摘　　要：将具有确定性参数的典型疲劳车辆模型改进为随机疲劳车流模型,采用小样本车辆轴重与等效疲劳应力数据拟合响应面的方法解决了车流作用下桥梁有限元应力时程分析耗时过长的问题。提出钢箱梁顶板-U肋疲劳损伤概率建模方法,最后将疲劳损伤概率模型应用于可靠度评估领域,揭示了车流参数对结构疲劳可靠指标的影响规律。研究结果表明:行车道重载车辆的较高占有率是导致其顶板-U肋疲劳可靠指标远低于超车道的重要原因;车辆轴重的增长致使钢箱梁疲劳可靠指标迅速降低,车重年线性增长系数由0增长至1%时,行车道顶板-U肋处100 a的疲劳可靠指标由3.42下降至0.72。随机疲劳车流模型与疲劳损伤概率模型具有一定的应用前景。The typical fatigue truck model with deterministic parameters is developed to be a stochastic vehicle flow model. The time-consuming problem of bridge finite element analysis under traffic flow loads is solved by using a response surface method to approximate the function between vehicle axle weight of a few training data and equivalent fatigue stresses. A probabilistic fatigue damage modeling method applies to ribto-deck details of steel box-girder bridges is presented. Finally,the fatigue damage model is applied to the reliability assessment,and the influence of traffic flow parameters on structural fatigue reliability is revealed.The numerical result indicates that（ 1） the higher occupancy rate of heavy vehicle flow in the slow lane is the main reason for the decrease of the fatigue reliability of corresponding rib-to-deck details compared with the fast lane;（ 2） the increase of the vehicle axle weight causes a rapid decrease of the fatigue reliability index of the steel box girders,when the annual linear growth factor increases from 0 to 1%,the fatigue reliability index of rib-to-deck detail in the slow lane decreases from 3. 42 to 0. 72. There is a promising application for the stochastic fatigue vehicle flow model and the probabilistic model of fatigue damage.

关 键 词：桥梁工程 钢箱梁 响应面 疲劳可靠度 随机车流 顶板-U肋 

分 类 号：U441[建筑科学—桥梁与隧道工程] U448.213[交通运输工程—道路与铁道工程]