脱粘对钢管混凝土拱桥动力特性影响研究

发布时间：2018-02-11 01:42

本文关键词： 脱粘动力特性钢管混凝土拱桥参数分析　出处：《长沙理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：脱粘是钢管混凝土拱桥在运营中的比较普遍的实际工程问题。为了解脱粘对桁架式钢管混凝土拱桥动力性能的影响,本文基于完全脱粘假设选取了恰当的连接单元,运用ANSYS软件建立了总溪河大桥脱粘与完全粘结模型。并研究不同脱粘位置及脱粘范围对钢管混凝土拱桥的动力特性的影响。最后对考虑不同的脱粘高度、不同含钢率、内法兰的作用和不同的轴向粘结刚度的钢管混凝土拱桥在全跨完全脱粘后的自振特性进行分析。主要研究成果如下:(1)桥梁发生脱粘后前十阶的振型的基本形状不会改变,只有与主拱肋相关的振型出现的顺序会发生变动。变动中以主拱肋的一阶对称与反对称竖弯振型提前为主。主要原因是主拱肋发生脱粘后会导致拱肋的面内刚度下降。(2)脱粘发生后主拱肋的各阶振型对应的频率会发生下降,且随着脱粘范围的增加,下降幅度也越大。脱粘对于面内反对称振型的频率影响尤为明显。不同脱粘位置相同的脱粘范围对主拱肋的各阶振型对应的频率的影响中,双侧拱脚脱粘大于单侧拱脚脱粘,单侧拱脚脱粘大于跨中拱肋脱粘。(3)全跨完全脱粘,脱粘模拟单元考虑的粘结强度在0.05MPa~0.3 MPa时,随着粘结强度的增加,桥梁整体的各阶振动频率均有所增加,但增幅较小。面内振型对应的频率对粘结强度的变化较为敏感。脱粘高度在0.5mm~3.5mm的范围内时,各阶振型对应的频率对脱粘高度的变化不敏感。含钢率的变化对桥梁面内振型频率的影响强于其对面外振型频率的影响。含钢率在5%~13.3%的范围内时,随着含钢率的增加,脱粘对钢管混凝土拱桥的各阶振动频率的影响会有所减弱。。内法兰能改善脱粘后钢管混凝土拱桥的动力性能。
[Abstract]:Debonding is a common practical engineering problem in the operation of CFST arch bridge. In order to remove the influence of adhesion on the dynamic performance of truss CFST arch bridge, a suitable connecting element is selected based on the assumption of complete debonding. The model of debonding and complete bonding of Tongxihe Bridge is established by using ANSYS software. The influence of different debonding position and range on the dynamic characteristics of concrete-filled steel tubular arch bridge is studied. Finally, considering different debonding heights and different steel content, the dynamic behavior of concrete-filled steel tubular arch bridge is studied. The effect of internal flange and the natural vibration characteristics of concrete-filled steel tube arch bridge with different axial bonding stiffness after full span debonding are analyzed. The main research results are as follows: 1) the basic shape of the first ten modes of the bridge after debonding will not change. Only the order in which the modes associated with the main arch rib appear will change. The first order symmetry and antisymmetric vertical bending mode of the main arch rib are dominant in the change. The main reason is that the in-plane stiffness of the arch rib will be caused by the debonding of the main arch rib. The frequency corresponding to the modes of each order of the main arch rib will decrease after the occurrence of debonding. With the increase of the range of debonding, the decreasing amplitude is larger. The effect of debonding on the frequency of in-plane antisymmetric mode is especially obvious. The effect of the same debonding range on the frequency corresponding to the modes of each order of the main arch rib is discussed. The debonding of bilateral arch foot is greater than that of unilateral arch foot, and that of unilateral arch foot is larger than that of mid-span arch rib. (3) the whole span is completely debonded. When the bond strength considered by the debonding simulation unit is 0. 05 MPA / 0. 3 MPa, the bond strength increases with the increase of bond strength. The vibration frequencies of the whole bridge are increased, but the increase is small. The frequency corresponding to the in-plane mode is more sensitive to the change of bond strength. When the debonding height is in the range of 0.5 mm to 3.5 mm, The frequency corresponding to each order mode is insensitive to the change of debonding height. The influence of the change of steel-containing ratio on the in-plane mode frequency of the bridge is stronger than that on the external mode frequency. When the steel content ratio is within the range of 5% or 13.3%, with the increase of the steel content, the influence of the change of the steel content on the in-plane mode frequency of the bridge is stronger than that of the external mode frequency. The influence of debonding on the vibration frequency of CFST arch bridge is weakened. The internal flange can improve the dynamic performance of CFST arch bridge after debonding.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441.3

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