基于实测数据的扁平钢箱温度梯度疲劳应力谱分析方法

发布时间：2018-02-22 04:47

本文关键词： 桥梁工程扁平钢箱梁极值模型拉丁超立方抽样温度梯度疲劳应力谱　出处：《计算力学学报》2017年04期 　论文类型：期刊论文

【摘要】：为研究扁平钢箱梁温度疲劳应力谱,以南溪长江大桥悬索桥主梁为研究对象,基于温度传感器长期实测数据,筛选实测数据的日温度极值,运用广义极值模型描述季节极值概率分布并采用极值外推方法得到设计基准期极值模型。引入拉丁超立方抽样(LHS)法对极值模型进行抽样,得到日温度极值样本。结合日温度极值样本和正弦函数模型,构建服役期内关注点的温度时程曲线。基于有限元ANSYS软件平台,分析不同温度梯度下关注点的应力效应,回归温度梯度与疲劳应力的线性关系式,依据温度梯度时程曲线与线性关系式模型,采用雨流计数法得到钢箱梁温度梯度疲劳应力谱。研究表明,模拟抽样生成的温度样本数据符合温度场的季节变化特征,样本概率模型与实测数据概率模型相对吻合。关注点温度梯度疲劳应力谱能够为扁平钢箱梁疲劳寿命设计提供参考。
[Abstract]:In order to study the temperature fatigue stress spectrum of flat steel box girder, the main girder of the suspension bridge of Nanxi Yangtze River Bridge is taken as the research object. Based on the long-term measured data of temperature sensor, the daily temperature extremum of the measured data is screened. Using the generalized extreme value model to describe the probability distribution of the seasonal extreme value and the extreme value extrapolation method to obtain the design base period extreme value model, the Latin hypercube sampling (LHS) method is introduced to sample the extreme value model. The temperature history curve of the concerned point during the service period is constructed by combining the daily temperature extreme sample and the sinusoidal function model. Based on the finite element ANSYS software platform, the stress effect of the concern point under different temperature gradients is analyzed. According to the linear relationship between temperature gradient and fatigue stress, according to the time history curve of temperature gradient and linear relation model, the temperature gradient fatigue stress spectrum of steel box girder is obtained by rain flow counting method. The temperature sample data generated by simulated sampling accord with the seasonal variation characteristics of temperature field, and the sample probability model is in good agreement with the measured data probability model. The temperature gradient fatigue stress spectrum of the concerned point can provide a reference for the fatigue life design of flat steel box girder.
【作者单位】：长沙理工大学土木与建筑学院;
【基金】：国家重点基础研究发展计划(973计划)(2015CB057701) 国家自然科学基金(51378081,51308073)资助项目
【分类号】：U441.5

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