摘要
全空间S-N曲线是利用时序准则进行钢箱梁正交异性桥面板疲劳评估的基础。首先基于钢桥设计规范给出的有限疲劳寿命区S-N曲线,从理论上推导了覆盖低周疲劳寿命区、有限疲劳寿命区和高周疲劳寿命区的一般全空间S-N曲线模型。进一步针对小型汽车和日常风等荷载引起的低水平应力幅以及地震和强风等荷载引起的高水平应力幅,引入高周疲劳损伤累积因子和低周疲劳强度调整因子分别对低水平应力幅和高水平应力幅造成的疲劳损伤进行计算,提出一种适用于钢箱梁正交异性桥面板疲劳评估的全空间S-N曲线模型。在此基础上对模型参数的几何意义进行了解释。最后采用正交异性桥面板顶板-U肋疲劳试验数据对模型参数进行了估计,得到了具有最佳拟合度的全空间S-N曲线和具有99%保证率的疲劳评估全空间S-N曲线。研究结果表明,该文提出的全空间S-N曲线模型能准确描述钢箱梁正交异性桥面板在各种应力幅下的疲劳损伤累积特性。研究结果可为钢箱梁正交异性桥面板的疲劳评估奠定基础。
The full range S-N curve plays a fundamental role in the fatigue evaluation of orthotropic bridge decks in steel box-girders when using the sequential law. The general full range S-N curve model, which covers the low-cycle range, the finite-life region, and the high-cycle region, is deduced theoretically based on the S-N curve in the finite-life region specified in design specifications for steel bridges. Furthermore, a full range S-N curve model used for evaluating the fatigue performance of orthotropic bridge decks in steel box-girders is developed. In the model, the fatigue damage accumulation factor and the fatigue strength amplification coefficient are adopted to compute the fatigue damages caused by small stress amplitudes in the high-cycle region and the influence of plastic strain on the fatigue strength in the low-cycle region, respectively. The effects of low stress amplitude caused by cars and sustained wind and high stress amplitudes caused by earthquakes and strong winds are estimated. Subsequently, the parameters in the proposed model are explained from the geometrical point of view. The full range S-N curve with the best goodness of fit and the full range S-N curve for fatigue evaluation with 99% reliability are formulated by using the data obtained from fatigue tests of rib-to-deck joints. The results indicate that the full range S-N curve model developed in this paper has strong ability to describe the accumulative characteristics of fatigue damage of orthotropic bridge decks in steel box-girders under fatigue loading with variable amplitudes. The proposed full range S-N curve is expected to provide a reference for fatigue evaluation of orthotropic bridge decks in steel box-girders.
出处
《工程力学》
EI
CSCD
北大核心
2017年第11期210-217,共8页
Engineering Mechanics
基金
国家自然科学基金项目(51308186)
江苏省优秀青年科学基金项目(BK20170097)
中国博士后科学基金项目(2014M560387)
关键词
桥梁工程
钢箱梁
疲劳评估
正交异性桥面板
时序准则
bridge engineering
steel box-girder
fatigue evaluation
orthotropic deck
sequential law
作者简介
朱太勇（1992-）,男,安徽人,硕士生,主要从事钢桥疲劳评估研究（E一mail：13329220539@163.com）;;通讯作者： 周广东（1982-）,男,四川人,副教授,博士,主要从事结构健康监测研究（E一mail：zhougd@hhu.edu.cn）. E一mail： zhougd@hhu.edu.cn;张欢（1992-）,女,江苏人,工程师,硕士,主要从事结构健康监测研究（E一mail：zhhuan1214@163.com）;;吴二军（1972-）,男,河北人,副教授,博士,主要从事工程结构平移、加固改造与监测研究（E一mail：wej@hhu.edu.cn）;;陈鑫（1983-）,男,江苏人,副教授,博士,主要从事结构振动控制及智能材料应用研究（E一mail：civil.chenxin@gmail.com）.
