【作者】 李彩霞；

【导师】 冯仲仁；

【作者基本信息】 武汉理工大学 ， 桥梁与隧道工程， 2004， 硕士

【摘要】 钢管混凝土，作为一种新的复合建筑材料，近些年来在土木工程中得到了广泛的应用。从90年至今的十多年的时间里，在我国得到了极大的发展，然而必须看到，对钢管混凝土拱桥设计理论的研究则相对落后于工程实践，在动力特性方面的研究更落后于静力特性方面的研究。 由于结构在动载作用下各截面的最大内力和位移都与结构自由振动时的频率和振动形式密切相关，因而寻求自振频率和振型是进行各项动力分析的前提和基础。本文在收集有关拱桥及动力学资料的基础上，以晴川桥为背景，通过使用有限元分析商业软件ANSYS建立了空间有限元模型，对晴川桥桥跨结构的自振频率进行了计算和分析；并分析了各种参数取值差异对自振特性结果的影响，我们主要考虑了设计参数(矢跨比、宽跨比)的影响；此外还对因此桥的结构构造(横撑布置、传力结构及吊杆布置)和钢管拱桥构件的材料特性(桥面刚度、拱肋刚度)的不同对自振特性的影响作了分析。根据对自振特性的理论分析，结合工程检测实例分析了自振特性在桥梁检测中的应用。 目前钢管混凝土拱桥正不断地向大跨度、轻型化方向发展，对其在动荷载(如车辆、风和地震等)作用下的动力响应研究更显得十分迫切。在晴川桥的瞬态动力分析中，模拟分析了当移动荷载以不同速度通过桥面时的时间历程动力响应以及在冲击荷载作用下桥跨结构的时间历程动力响应，并对桥跨结构在移动荷载和冲击荷载作用下的动力放大系数作了较为详细的分析。 最后我们将有限元计算的结果与动载试验的成果进行了对比分析，结果表明有限元模拟结果与实测成果差别不大，能较好的反映该桥的动力特性。 本文通过对晴川桥的动力特性进行有限元模拟，论述了影响下承式钢管混凝土拱桥动力特性的多种因素，并得出了一些结论。这为该桥的动力测试提供一定的参考；同时还可为桥梁使用过程中的健康检测和维护提供基础性数据。更多还原

【Abstract】 As a new multiple construction material, concrete-filled steel tube has been used widely in civil engineering hi the past years. At the same time, concrete-filled steel tubular arch bridge has been deeply developed in our country since 1990. But the research of design theory of concrete-filled steel tubular arch bridge trails the engineering practice; especially the study of dynamic performance trails the study of static performance.Because the greatest internal force and displacement of every section when the structure is under the dynamic loads are nearly correlative with the frequencies and the vibrational formats when the structure is under the natural vibration, seeking natural vibration frequencies and modes is the precondition and base to carry through every dynamic analysis. In the thesis, on the basis of existing data collected of arch bridges and dynamics, taking the example of Qingchuan Bridge, establish 3-D finite element model of it with software ANSYS, and calculate and analyze its natural vibration frequencies, and analyze the effects of natural vibration feature of the differences of structure parameters. Some factors, such as design parameters (the ratio between height vector and span, the ratio between width and span), Furthermore, because of the different bridge structure, such as the arrangements of cross braces, the structure to pass on force, and the arrangements of suspenders, and the distinctness of material characteristics of bridge components, such as the rigidity of bridge deck and arch rib, the natural vibration characteristic is influenced. The thesis analyzes the effects. According to the theory analysis of natural vibration feature, the use of natural vibration feature in bridge test is analyzed combined with engineering testing practice.As concrete-filled steel tubular arch bridges develop in the direction of large-span and lightweight style, the study on dynamical response of the structure under live loads such as vehicles, wind and earthquake is in need. During the transient dynamic analysis of Qingchuan Bridge, the tune history responses of the structure under uniform velocity moving load and impact load are analyzed, and the amplification coefficients of deflection and internal factors of the structure are intensively analyzed.At last, the results calculated by finite element software and the results under the test of moved loads are compared and analyzed. The analytic results suggest that the discrimination between both is little, so the results simulated by finite element software can reflect the dynamic characteristic of the bridge.By the finite element simulation to Qingchuan Bridge dynamic characteristic, the thesis discusses manifold factors which influence the dynamic characteristic of half-through concrete filled steel tubular arch bridge, and gets some conclusions. It will offer reference to the bridge dynamic test, and provide basic datum for the health examination and maintenance during its use.更多还原