XFEM及其在正交异性钢桥面板疲劳裂纹扩展中的应用  

XFEM and Its Application to Fatigue Crack Extension of Orthotropic Steel Bridge Deck

作　　者：渠昱[1,2] 曾勇[1,2] 顾安邦[1,2] 杜柏松[1,2] QU Yu;ZENG Yong;GU Anbang;DU Baisong(State Key Laboratory Breeding Base of Mountain Bridge and Tunnel Engineering,Chongqing Jiaotong University, Chongqing 400074 ,P. R. China;Mountain Bridge Structure and Materials Engineering Research Center of Ministry of Education, Chongqing Jiaotong University,Chongqing 400074, P. R. China)

机构地区：[1]重庆交通大学山区桥梁与隧道工程国家重点实验室培育基地,重庆400074 [2]重庆交通大学山区桥梁结构与材料教育部工程研究中心,重庆400074

出　　处：《重庆交通大学学报（自然科学版）》2018年第4期21-27,共7页Journal of Chongqing Jiaotong University(Natural Science)

基　　金：国家自然科学基金项目(51478071);山区桥梁与隧道工程国家重点实验室培育基地开放基金项目(CQSLBF-Y14;CQSLBF-Y16-10)

摘　　要：为了研究某大桥扁平钢箱梁正交异性钢桥面板模型试验中出现裂纹的原因,根据试验模型创建了三维扩展有限元(XFEM)模型进行整节段数值计算,利用不连续伽辽金扩展有限元(DG-XFEM)对裂纹扩展进行了模拟。结果表明:弧形开孔与U肋连接附近为高应力区,该高应力与几何不连续、焊接缺陷引起的应力集中及残余应力等不利因素叠加,使得弧形开孔与U肋连接附近成为疲劳最敏感的部位,即疲劳裂纹产生地;裂纹扩展的初始阶段与主应力等值线垂直,沿最大主应力方向扩展;裂纹出现的位置、扩展路径和长度与试验结果符合很好,与实际桥梁裂纹出现的位置和形态基本一致,也与裂纹扩展的基本理论一致。In order to study the cause of crack occurred at the orthotropic steel bridge deck test model of a long span flat steel box girder,the 3-D segment model was established and calculated by extended finite element method（ XFEM） on the basis of the experiment model,and the crack propagation simulation was carried out by the discontinuous Galerkin finite element method（ DG-XFEM）.The results show that the places near the weld tip of connection of U rib and the curved opening are the high stress zones.This high stresses superimposed on such unfavorable factors as stress concentration caused by geometrical discontinuity,weld defects and built-in stresses make the places near the connection of U rib and the curved opening as the most sensitive sites of fatigue,that is fatigue crack producing area.The initial stage of crack growth is perpendicular to the principal stress isocline and extends along the direction of the maximum principal stress. The position,propagation path and length of the crack are in good agreement with the test results,which is consistent with the position and shape of the cracks in the actual bridge,and is also consistent with the basic theory of crack propagation.

关 键 词：桥梁工程 扩展有限元 不连续伽辽金扩展有限元 正交异性钢桥面板 疲劳裂纹扩展 横隔板弧形开孔 

分 类 号：U441.4[建筑科学—桥梁与隧道工程] U443.32[交通运输工程—道路与铁道工程]