大跨度钢管翼缘组合梁桥车桥耦合振动性能分析

为了研究钢管翼缘组合梁桥的动力性能，通过有限元软件ABAQUS建立了三维车桥耦合振动模型，采用了隐式动力学分析了路面平整度、车辆载重、速度、上翼缘钢管内填混凝土等级和含钢率等因素对管翼缘组合梁桥动力性能的影响，以及与管翼缘组合梁竖向刚度等效的工字钢梁和混凝土梁的动力性能，得出了以下结论：随着路面不平顺程度的增大，管翼缘组合梁的动力响应呈几何倍数增长，并且只有当路面等级为B时才与现行《公路桥涵设计通用规范》中公式计算的动力冲击系比较吻合；车辆载重与其跨中挠度呈线性相关；速度对其的影响比较复杂，当车辆速度超过60 km/h时，其动力响应随速度增大呈非线性增长；上翼缘内混凝土等级和含钢率对其动力影响极小；相对于等效工字钢梁和等效混凝土梁，管翼缘组合梁桥重量轻，整体弹性模量较小，同等荷载下跨中挠度比较大。通过上述的动力性能研究为以后大力发展此类型桥提供技术保障。

Performance Analysis of Vehicle-Bridge Coupling Vibration of Large-span Concrete-filled Steel Tube Flange Composite Girder Bridge

In order to study the dynamic performance of the steel tube flange composite beam bridge, a three-dimensional vehicle-bridge coupled vibration model was established through the finite element software ABAQUS, and implicit dynamics are used to analyze the influence of factors such as road surface roughness, vehicle load, speed, concrete grade and steel content of the upper flange steel tube on the dynamic performance of the tube flange composite beam bridge, as well as the dynamic performance of I-beam and concrete beams equivalent to the vertical stiffness of tube flange composite beams. The result shows that, with the increase of road surface roughness, the dynamic response of tube-flange composite beams increases geometrically, and it is more consistent with the dynamic impact system calculated by the formula in the current the General Code for Design of Highway Bridges and Culverts JTG D60-2015 when the road surface level is B. The vehicle load is linearly related to its deflection. The influence of speed on it is more complicated. When the vehicle speed exceeds 60 km/h, its dynamic response increases nonlinearly with the increase of speed. The concrete grade and steel content in the upper flange affect it the dynamic influence is extremely small. Compared with the equivalent I-beam and equivalent concrete beam, the tube flange composite beam bridge which has a smaller overall elastic modulus is light in weight and has a larger deflection under the same load. The above-mentioned dynamic performance research will provide technical support for vigorously developing this type of bridge in the future.