考虑循环作用特征的公路桥梁荷载谱疲劳分析方法  

Fatigue Analysis Method through Load Spectrum Considering Cyclic Characteristics for Highway Bridges

作　　者：孙良凤 郑祥隆 沈明江 SUN Liangfeng;ZHENG Xianglong;SHEN Mingjiang(The Architectural Design&Research Institute of Zhejiang University Co.,Ltd.,Hangzhou,Zhejiang 310027,China;Center for Balance Architecture,Zhejiang University,Hangzhou,Zhejiang 310058,China)

机构地区：[1]浙江大学建筑设计研究院有限公司,浙江杭州310027 [2]浙江大学平衡建筑研究中心,浙江杭州310058

出　　处：《中外公路》2024年第3期164-174,共11页Journal of China & Foreign Highway

基　　金：国家自然科学基金青年科学基金资助项目(编号:52208217)

摘　　要：为了兼顾疲劳荷载谱的分析精度和实用性,该文提出了适用于单车加载和车流加载的荷载模型损伤效应比例系数和循环作用特征长度指标,通过研究典型疲劳车辆疲劳损伤效应一般规律,构建从单车作用到车流随机作用的疲劳荷载谱损伤分析方法。结果表明:单辆疲劳车引起的疲劳损伤可以在集中荷载效应基础上进行比例换算,由影响线绝对面积换算的循环作用特征长度指标对单车疲劳分析有较好的适用性。随机车流引起的疲劳损伤受到桥梁跨径和车流密度的共同影响,在短跨径桥梁中,损伤效应对车流密度不敏感,车流密度的增加甚至会造成一部分结构内力幅的减小;当跨径超过一定临界值时,车流密度的影响显著加剧;由影响线积分面积换算的循环作用特征长度指标更适用于车流疲劳损伤效应分析。荷载谱等效应力幅应结合交通流状态谱进行分析,多车道损伤效应系数指标的构建应考虑车辆相遇概率、循环作用特征长度指标的影响。To consider the analysis accuracy and practicability of fatigue load spectrums,this paper proposed the proportional coefficient of damage effects and the cyclic characteristic lengths corresponding to singlevehicle loading and multi-vehicle loading.Through the investigation of general fatigue damage effects of typical fatigue vehicles,it constructed a damage analysis method of fatigue load spectrum from single-vehicle loading to multi-vehicle loading for load spectrum.The results show that the fatigue damage caused by a single fatigue vehicle can be scaled based on the concentrated load effects,and the cyclic characteristic length converted from the absolute area of influence lines has good applicability for the fatigue analysis of singlevehicle loading.The fatigue damage caused by random traffic flow is affected by both the bridge span and traffic flow density.In short-span bridges,the damage effect is not sensitive to traffic flow density,and the increase in traffic flow density may even lead to a decrease in the force amplitude in some cases.When the bridge span exceeds a certain critical value,traffic flow density shows a significantly increased influence,and the cyclic characteristic length converted from the integral area of influence lines is more suitable for the effect analysis of fatigue damage of traffic flow.The equivalent stress amplitude of the load spectrum shall be analyzed in combination with the traffic flow state spectrum,and the effects of vehicle encounter probability and cyclic characteristic length shall be considered for the formulation of multi-lane damage effect factors.

关 键 词：公路桥梁 荷载谱 疲劳荷载模型 疲劳分析 循环作用特征长度 

分 类 号：U441[建筑科学—桥梁与隧道工程]