模拟轮载作用下钢桥面板RD节点疲劳寿命计算方法对比分析  

Comparative Analysis of Fatigue Life Calculation Methods for Rib-To-Deck Joints in Steel Bridge Decks Under Simulated Wheel Load

作　　者：田亮 邢守航 樊立龙 赵健 程斌[4] 赵雪敏 Tian Liang;Xing Shouhang;Fan Lilong;Zhao Jian;Cheng Bin;Zhao Xuemin(Tianjin Key Laboratory of Civil Structure Protection and Reinforcement,Tianjin Chengjian University,Tianjin 300384,China;School of Civil Engineering,Tsinghua University,Beijing 100084,China;China Railway Construction Bridge Engineering Bureau Group Co.,Ltd.,Tianjin 300300,China;School of Naval Architecture,Ocean and Civil Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]天津城建大学天津市土木建筑结构防护与加固重点实验室,天津300384 [2]清华大学土木工程系,北京100084 [3]中国铁建大桥工程局集团有限公司,天津300300 [4]上海交通大学船舶海洋与建筑工程学院,上海200240

出　　处：《华东交通大学学报》2023年第4期76-85,共10页Journal of East China Jiaotong University

基　　金：国家自然科学基金项目(51708346);国家重点研发计划项目(2016YFB1200602-28,2016YFB1200601-B27);中国铁建股份有限公司科技重大专项(2020-A01);天津市企业科技特派员项目(22YDTPJC00210);天津市科技开发项目(19YDL,SF00030)。

摘　　要：为深入研究RD(rib-deck)节点的疲劳性能,通过模拟车轮荷载对RD节点实施中心加载,得到了相应热点应力幅下的节点疲劳寿命。采用ABAQUS建立了钢桥面板RD节点的三维实体有限元模型,在有效数值模型的基础上,分别采用热点应力法和临界距离理论对RD节点的疲劳寿命进行了对比分析。研究结果表明:同一精度网格下采用两点外推法和三点外推法得到的热点应力结果比较接近,而采用临界距离理论的点法得到的特征应力则小于线法得到的特征应力;采用国际焊接协会(IIW)推荐的FAT 90曲线得到的评估结果过于保守,而FAT 125曲线的预测结果相对接近试验值。临界距离理论相比热点应力法能得到更准确的预测结果,其中点法和线法得到的预测值与试验值分别相差17%、32%;总体而言,热点应力法和临界距离理论均能得到相对保守的疲劳寿命预测结果,两种方法用于钢桥面板典型焊接节点的疲劳性能评估是可行且偏于安全的,但点法的预测精度更高,且实际应用中也较为便捷。In order to further study the fatigue performance of RD joint,the RD joint was subjected to central loading by simulating wheel loads,and the fatigue life of RD joint under corresponding hot spot stress range was obtained by conducting fatigue tests.The 3D solid finite element model of RD joint in steel bridge decks was established by using ABAQUS.Based on the effective numerical model,the fatigue life of RD joint was compared and analyzed by using the hot spot stress method and the critical distance theory respectively.The results show that under the same finite element mesh,the hot spot stress results obtained by two-point extrapolation and three-point extrapolation are relatively close,while the characteristic stress obtained by point method using the critical distance theory is smaller than that obtained by line method.The evaluation results obtained by FAT90S-N curve recommended by IIW are too conservative,while the prediction results of FAT125 S-N curve are relatively close to the measured value.Compared with the hot spot stress method,the critical distance theory can get more accurate prediction results,in which the prediction errors obtained by the point method and the line method are 17% and 32% respectively.In general,both the hot spot stress method and the critical distance theory can get relatively conservative fatigue life prediction results.Therefore,the two methods are feasible and safe for fatigue behavior evaluation of typical welded joints in steel bridge decks.However,the point method has higher prediction accuracy and is also more convenient in practical application.

关 键 词：正交异性桥面板 疲劳试验 疲劳寿命 热点应力法 临界距离理论 

分 类 号：U443.32[建筑科学—桥梁与隧道工程]