考虑非线性累积损伤的大跨多荷载桥梁的疲劳可靠度评估  

Fatigue Reliability Analysis of Multi-loading Suspension Bridges Considering Nonlinear Accumulative Damage

作　　者：陈志为[1,2] 徐幼麟[3] 

机构地区：[1]厦门大学土木工程系,福建厦门361005 [2]江苏省工程力学分析重点实验室,江苏南京210096 [3]香港理工大学土木与结构工程系

出　　处：《西南交通大学学报》2014年第2期213-219,共7页Journal of Southwest Jiaotong University

基　　金：国家自然科学基金资助项目(NSFC-51108395);中央高校基本科研业务费专项资金资助项目(2012121032);江苏省工程力学分析重点实验室开放课题基金资助项目

摘　　要：针对大跨多荷载桥梁疲劳损伤累积非线性过程中的大量不确定性,对火车、汽车与风荷载作用下的大跨悬索桥,利用连续损伤模型提出了一个疲劳可靠度评估方法.首先,在连续损伤模型基础上,对模型参数进行分析;然后,根据工程应用的需要,适当简化疲劳模型,在连续损伤模型中引入合适的随机变量,定义疲劳可靠度分析的极限状态函数,假定多种未来可能的交通荷载和荷载增长模式,利用蒙特卡洛方法产生随机变量并计算失效概率;最后以香港青马大桥为例,讨论了该桥在不同荷载状况下使用120年后的疲劳失效概率.研究发现:若保持当前的交通状态,桥梁可保持良好状况,但未来交通荷载的快速增长会导致结构提前失效.Taking into account uncertainties in the nonlinear process of fatigue damage accumulation for fatigue reliability analysis of multi-loading long-span bridges,a fatigue reliability assessment method for a long suspension bridge under combined highway,railway,and wind loadings was proposed using a continuum damage model （CDM ）. First,the CDM based on continuum damage mechanics was briefly introduced,and main model parameters were analyzed. Then,a simplified CDM was proposed for further application to bridge structures. A limit state function for fatigue reliability analysis based on CDM was defined by introducing proper random variables into the CDM. The Monte Carlo simulation （MCS）was adopted to generate the random variables and to calculate the failure probability. Finally, the Tsing Ma Bridge in Hong Kong was taken as a case study,and the failure probabilities of the bridge at the end of 120 years were estimated for different loading scenarios. The results indicate that the health condition of the bridge in fatigue is satisfactory under the current traffic conditions,but attentions should be paid to future traffic growth because it will largely accelerate the damage growth.

关 键 词：疲劳 悬索桥 风 铁路 公路 非线性损伤 可靠度 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] TU311.3[交通运输工程—道路与铁道工程]