车-简支梁桥耦合振动系统中全局最大动力响应研究

本文采用四分之一车辆模型和等截面简支梁模型，建立了车-桥耦合振动计算模型，分析了车辆匀速驶过桥梁时，桥梁动挠度、动弯矩、动剪力的全局最大值及发生的位置.进一步分析计算了车速、车距和桥梁模态截断阶数对桥梁动挠度、动弯矩、动剪力全局最大值的影响.结果表明，车速对桥梁动挠度、动弯矩、动剪力全局最大值影响较大，全局最大动挠度和全局最大动弯矩均出现在跨中附近，车速不同位置也不同，而全局最大动剪力均出现在车辆下桥的梁端；两车同时上桥时，前后车车距越大，桥梁动挠度、动弯矩、动剪力全局最大值越小，当达到一定车距时，三者不再减小且与单车情况相同；为提高桥梁动挠度、动弯矩、动剪力全局最大值计算精度，桥梁模态截断阶数宜分别大于3阶、6阶、7阶.

The Global Maximum Dynamic Responses Of Vehicle-Simply

In this paper, a quarter vehicle model and a uniform cross section simply supported beam model are used to establish a vehicle bridge coupling system. The global maximum values and its location on the bridge of dynamic deflection, dynamic bending moment and dynamic shear force are analyzed when the vehicle travelling through the bridge at a constant speed. The effects of vehicle speed, distance between front and rear vehicles, and bridge modal truncation order on the global maximum value are further analyzed and calculated. The results show that the vehicle speed has a greater impact on the global maximum value of dynamic deflection, dynamic bending moment, and dynamic shear force of the bridge. Both the global maximum dynamic deflection and the global maximum dynamic bending moment appear in the mid-span range, the locations are different with different vehicle speeds. The global maximum dynamic shear force appears at the beam end of the vehicle exiting the bridge. when two vehicles are on the bridge at the same time, the greater the distance between the front and rear vehicles, the smaller the global maximum value of dynamic deflection, dynamic bending moment, and dynamic shear force of the bridge. When a certain distance is reached, the global maximum values are no longer reduced and are the same as the case of a single vehicle. In order to improve the calculation accuracy of the dynamic deflection, dynamic bending moment, and dynamic shear force of the bridge, the bridge modal truncation order should be greater than 3 orders, 6 orders and 7 orders, respectively.