列车动力荷载作用下大跨度斜拉桥局部振动响应研究

发布时间：2018-08-16 07:37

【摘要】：为研究列车动力荷载引起的大跨度斜拉桥主梁和桥面板局部动力响应,基于车-桥耦合动力学理论建立了列车-轨道-斜拉桥空间耦合动力学模型。采用固定界面模态综合法和等效正交异性板法建立大跨度斜拉桥精细化三维有限元模型,车辆简化为具有二系悬挂的31自由度弹簧-质量模型,轮轨关系采用可分离的三维轮轨滚动接触模型。以主跨为1 092 m的沪通长江大桥为例,研究了轨道不平顺激励条件下高速列车行驶引起的桥面板和主桁架梁的动力响应特征及分布规律。研究结果表明:固定界面模态综合法既可以有效减少模型自由度数目,又可以反映桥梁局部动力响应;等效正交异性板法虽能较好地反映桥面板的局部振动,但由于没有考虑等效前后主梁整体刚度的一致性,故所计算的主梁振动位移偏差较大;由于桥面板局部竖向刚度较小,桥梁行车线正下方的桥面板竖向加速度远大于主梁桁架节点竖向加速度,建议我国相关铁路桥梁规范在评估大跨度板桁斜拉桥振动加速度时,考虑桥面板局部振动的影响;列车动力荷载作用下主梁桁架杆件应力冲击系数较小,动力效应不显著。
[Abstract]:In order to study the local dynamic response of the main girder and deck of a long-span cable-stayed bridge caused by train dynamic load, a space-coupling dynamic model of train-track cable-stayed bridge is established based on the vehicle-bridge coupling dynamics theory. Using the fixed interface modal synthesis method and the equivalent orthotropic plate method, the fine three-dimensional finite element model of long-span cable-stayed bridge is established, and the vehicle is simplified as a 31-DOF spring-mass model with two-system suspension. The wheel / rail relationship is based on a three-dimensional wheel / rail rolling contact model. Taking the Hutong Yangtze River Bridge with a main span of 1092m as an example, the dynamic response characteristics and distribution law of deck slab and main truss beam caused by high-speed train running under irregularity of track are studied. The results show that the fixed interface modal synthesis method can not only effectively reduce the number of the model degrees of freedom, but also reflect the local dynamic response of the bridge, although the equivalent orthotropic plate method can better reflect the local vibration of the bridge deck plate, However, due to not considering the consistency of the overall stiffness of the main beam before and after equivalent, the vibration displacement deviation of the main beam calculated is larger, and the local vertical stiffness of the bridge deck is smaller. The vertical acceleration of the deck plate is much higher than that of the main girder truss joint directly under the bridge driving line. It is suggested that the local vibration of the bridge deck should be taken into account in the evaluation of the vibration acceleration of the long-span plank-truss cable-stayed bridge in the relevant railway bridge codes of our country. Under the action of train dynamic load, the stress impact coefficient of main girder truss member is small, but the dynamic effect is not significant.
【作者单位】：中南大学土木工程学院;中南大学高速铁路建造技术国家工程实验室;西南交通大学牵引动力国家重点实验室;
【基金】：国家重点研发计划项目(2017YFB1201204) 国家自然科学基金(51378511;51678576) 牵引动力国家重点实验室开放课题(TPL1601)
【分类号】：U441.3;U448.27

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