斜拉桥钢桥面板挖孔细节群的数字畸变疲劳试验  

Digital distortion-induced fatigue tests on diaphragm cutout detail group in steel bridge decks of cable-stayed bridges

作　　者：王春生[1] 许璐巍 李璞玉 WANG Chunsheng;XU Luwei;LI Puyu(Highway School,Chang’an University,Xi’an 710064,China)

机构地区：[1]长安大学公路学院,西安710064

出　　处：《东南大学学报(自然科学版)》2025年第1期66-77,共12页Journal of Southeast University:Natural Science Edition

基　　金：国家自然科学基金资助项目(51578073);长安大学中央高校基本科研业务费专项资金资助项目(300102214904)。

摘　　要：为研究斜拉桥钢桥面板横隔板挖孔细节群的畸变疲劳机理,考虑疲劳应力、焊接残余应力、焊接缺陷等多场耦合作用,建立了斜拉桥全桥足尺数字疲劳孪生模型,实现了钢桥面板典型细节群的数字畸变疲劳试验与模拟。焊接数字孪生模拟时,采用与单元温度相关联的热对流参数表达,可显著改善焊接温度场和残余应力场模拟准确度。数字畸变疲劳试验与模拟结果表明,横隔板挖孔细节群的畸变疲劳裂纹尖端等效应力强度因子幅均大于门槛值,该细节群初始裂纹在运营卡车荷载作用下易于扩展。应变能释放率分析结果表明,横隔板挖孔细节群的畸变疲劳裂纹均是以Ⅰ型裂纹为主导的Ⅰ-Ⅱ-Ⅲ型复合型裂纹,扩展全过程3种类型裂纹耦合特征显著。该研究成果可为斜拉桥钢桥面板抗疲劳设计与维护提供依据。To investigate the distortion-induced fatigue mechanism of the diaphragm cutout detail group in steel bridge deck of cable-stayed bridge,a cable-stayed bridge full-scale digital fatigue twin model was estab-lished,considering the multi-field coupling effects of fatigue stress,welding residual stress and welding de-fects.This model enabled the digital test and simulation of distortion-induced fatigue in steel bridge deck typi-cal detail groups.During the welding digital twin simulation,the simulation accuracy of the welding tempera-ture field and residual stress field were significantly improved using thermal convection parameters related to element temperature.The digital distortion-induced fatigue test and simulation results show that the equivalent stress intensity factor amplitude at the distortion-induced fatigue crack tips are greater than the threshold,mak-ing the initial cracks at the detail group more likely to grow under the load of operating trucks.The results of strain energy release rate analysis show the distortion-induced fatigue cracks at the diaphragm cutout detail group are all mixed-mode cracks of ModesⅠ,Ⅱ,andⅢled by ModeⅠ.The coupling characteristics of the three modes cracks are significant during the whole propagation process.The research results can provide the basis for the anti-fatigue design and maintenance of the steel bridge deck in cable-stayed bridges.

关 键 词：桥梁工程 斜拉桥 钢桥面板 畸变疲劳 数字疲劳试验 复合型裂纹 累积应变能释放率 

分 类 号：U441.4[建筑科学—桥梁与隧道工程]