摘要
车辆轮迹横向分布是钢桥面板焊缝处产生随机应力谱的一项关键因素,加之焊接缺陷形态的随机性,诱发钢桥面板疲劳裂纹随机扩展行为。为了研究钢桥面顶板焊缝处疲劳裂纹的随机扩展特性,基于断裂力学理论与扩展有限元方法分析了轮迹横向分布对钢桥面板顶板焊根和焊趾等效应力强度因子的影响规律,揭示了轮迹横向分布离散度、初始裂纹深度和初始裂纹形态比对焊缝处疲劳裂纹随机扩展路径分布的影响规律。结果表明:轮载中心处于U肋正上方中心和焊缝中心位置分别为顶板焊趾和焊根的最不利横向加载工况;车辆轮迹横向分布对顶板焊根和顶板焊趾疲劳裂纹前缘应力强度因子影响差异显著,顶板焊根最大等效应力强度因子为85.99 MPa·mm^(1/2),比顶板焊趾增加了6.72%;轮迹横向分布离散度和初始裂纹深度与钢桥面板焊缝处疲劳裂纹随机扩展路径分布离散程度成正相关,初始裂纹形态比与其成负相关;焊缝细节初始裂纹深度越大,车辆荷载对其横向影响范围越大;焊缝细节初始裂纹形态比越大,车辆荷载对其横向影响范围变化不明显。
Lateral distribution of vehicle wheel tracks is a key factor to generate random stress spectra at weld joints of a steel bridge deck.In addition,the randomness of welding defect morphology induces random propagation behavior of fatigue cracks in steel bridge deck.Here,to study random propagation characteristics of fatigue cracks at weld joints of steel bridge deck top plate,based on fracture mechanics theory and extended finite element method,effects of lateral distribution of wheel tracks on equivalent stress intensity factors of weld root and weld toe of steel bridge deck top plate were analyzed to reveal effects of lateral distribution dispersion of wheel tracks,initial crack depth and initial crack morphologic ratio on random propagation path distribution of fatigue cracks at weld joints.The results showed that wheel load center being located directly above U-rib center and weld joint center,respectively are the most unfavorable lateral loading conditions for top plate weld toe and weld root;effects of lateral distribution of vehicle wheel tracks on stress intensity factor of fatigue crack front edge of top plate weld root and those on top plate weld toe have a significant difference,the maximum equivalent stress intensity factor of top plate weld root is 85.99 MPa·mm^(1/2),it is 6.72% higher than that of top plate weld toe;dispersion degree of lateral distribution of wheel tracks and initial crack depth are positively correlated with random propagation path distribution dispersion degree of fatigue cracks at weld joints of steel bridge deck,while they are negatively correlated with initial crack morphology ratio;the larger the initial crack depth of weld details,the bigger the lateral influence range of vehicle load on it;the larger the initial crack morphology ratio of weld details,the less obvious the change of lateral influence range of vehicle load on it.
作者
鲁乃唯
刘静
王凯
王鸿浩
LU Naiwei;LIU Jing;WANG Kai;WANG Honghao(School of Civil Engineering,Changsha University of Science&Technology,Changsha 410114,China;Hunan Provincial Engineering Technology Research Center of Safety Control Technology and Equipment of Bridge Engineering,Changsha University of Science&Technology,Changsha 410114,China;Hunan Construction Quality Inspection Center Co.,Ltd.,Changsha 410114,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2024年第1期193-201,共9页
Journal of Vibration and Shock
基金
国家重点研发计划项目(2021YFB260090)
国家自然科学基金项目(51908068,52178108)
湖南省自然科学基金项目(2021JJ30720)
湖南省青年科技人才项目(2022RC1181)
长沙理工大学桥梁工程领域开放基金资助项目(18KC01)。
关键词
桥梁工程
钢桥面板
扩展有限元
随机扩展路径
轮迹横向分布
应力强度因子
bridge engineering
steel bridge deck
extended finite element
random propagation path
lateral distribution of wheel tracks
stress intensity factor
