摘要
车辆荷载下斜拉桥主梁频繁纵向振动使支座、阻尼器等磨损,影响行车安全性。将引起主梁纵向位移的移动荷载等效为作用于主梁的纵向荷载,基于一阶模态将斜拉桥等效为单自由度体系,求解此等效单自由度体系在等效纵向激励下振动响应,通过叠加原理得到多个移动荷载下斜拉桥主梁纵向振动响应估算公式,并验证了此估算方法有效性,研究了列车荷载下斜拉桥主梁纵向振动规律。结果表明:基于等效一阶模态体系的估算方法得到的桥梁响应与数值分析结果保持一致,其最大值误差在10%范围内,列车荷载下漂浮体系斜拉桥主梁发生纵向共振,这是单个荷载过桥时的等效纵向加载频率与桥梁一阶纵向振动频率接近导致,提出的估算方法能有效地揭示此规律。
Frequent longitudinal vibration of main beam of a cable-stayed bridge under vehicle load causes wear of bearings,dampers,etc.to affect driving safety.Here,moving load to cause longitudinal displacement of main beam was equivalent to longitudinal load acting on main beam.Based on its first-order mode,a cable-stayed bridge was equivalent to a single-DOF system.The vibration response of this equivalent single-DOF system under equivalent longitudinal excitation was solved.The estimation formula for longitudinal vibration response of cable-stayed bridge deck under multiple moving loads was obtained using the superposition principle,and the effectiveness of this estimation method was verified.Finally,the longitudinal vibration law of cable-stayed bridge deck under train load was studied.The results showed that bridge responses obtained with the proposed estimation method based on the equivalent first-order mode system is consistent with numerical analysis results,their maximum value errors are less 10%;longitudinal resonance of main beam of floating system cable-stayed bridge under train load is caused due to the equivalent longitudinal loading frequency when a single moving load passing through bridge being close to the first-order longitudinal natural frequency of bridge,the proposed estimation method can effectively reveal this law.
作者
吕龙
余帅
LYU Long;YU Shuai(College of Environment and Civil Engineering,Chengdu University of Technology,Chengdu 610059,China;State Key Lab of Bridge Safety and Resilience,China Merchants Chongqing Communications Technology Research Design Institute Co.,Ltd.,Chongqing 400067,China;School of Civil Engineering,Chongqing University,Chongqing 400044,China)
出处
《振动与冲击》
北大核心
2025年第19期158-165,共8页
Journal of Vibration and Shock
基金
国家自然科学基金(52108113)
重庆市博士后特别资助(2022CQBSHTB2014)
桥梁工程结构动力学国家重点实验室开放基金(202204)。
关键词
移动荷载
斜拉桥
纵向振动
等效荷载
动力响应
moving load
cable-stayed bridge
longitudinal vibration
equivalent load
dynamic response
