钢管混凝土肋拱桥自振特性及汽车荷载作用下动力响应的研究-桥梁与遂道工程专业论文.docxVIP

摘 摘 要 本文首先分析了钢管混凝土这种新兴组合材料的受力特 点，综述了钢管混凝土拱桥和车辆荷载作用下桥梁结构振动研 究的历史与现状。在此基础上以瓷都大桥为例，采用空间粱单 元、三维杆件单元以及板单元模拟实桥，建立了全桥自振特性 分析模型，计算得到了其自振特性。在自振特性计算中采用钢 管混凝土统一理论，将钢管混凝土化为单一材料计算钢管混凝 土构件的材料特性及构件的截面几何特性。全面分析、比较了 各部分结构参数的改变对自振特性的影响。对此类结构自振特 性的计算模型进行了综合评价。 ＼(采用三维汽车模型，基于模态综合法的原理将车辆．钢管 混凝土拱桥视为相互作用的动力系统，并考虑车辆在桥上的不 同位置以及不同车辆数目和不同车速等复杂情况，推导了车． 桥体系的动力平衡方程组，用逐步积分法求解。在验证本文所 编制程序的基础上，应用这种方法首次从理论上计算了汽车车 辆通过桥梁时车辆和钢管混凝土拱桥的空间动力响应。针对实 际桥梁结构的多种不同工况，进行了大量的数值计算，得到了 一些对钢管混凝土拱桥研究、设计有价值的结论。k 关键词：钢管混凝土拱桥；自由振动：车硬妒梁耦合振动；模 态综合法；冲击系数；数值解法 j匕京5嗵大掌司n}论文ABSTRACT j匕京5嗵大掌司n}论文 ABSTRACT On the basis of analyzing the mechanical characteristics of Concrete Filled Steel Tubular(CFST)members and reviewing the development of CFST arch bridges and the state—of-art of bridge vibration study,the paper sets up the free vibration analysis model of CFST ribbed arch bridge by using spatial beam elements，three—dimensioned bar elements and slab elements to stimulate real bridge，obtaining the free vibration charatistics of Cidu bridge，a real bridge in Jiangxi province of China．A new method is suggested in the paper,which regards CFST as a single material，to calculate the material and geometry characteristic of CFST members．The affect ofbridge components to the丘ee vibmtion is evaluated． By regarding the bridge and vehicles as a whole dynamic system，the paper constructs an effective method to analyze the arch-bridge dynamic Interaction under moving vehicle loads．T11is method derives the governing equations of bridge·-vehicle system with three··dimensional automobile model and spatial freedoms of bridge，solving the goveming equations by Newmark·B method after reducing the bridge’s freedoms witll its mode—shapes which are obtained bv FEM．As there is no special restriction for the bridge structure and the automobile mode is standardized，the proposed method can consider the cases with different bridge structures and automobile modes．After proving the designed computer program，the method is adopted to study the dynamic response