摘要
为研究斜拉桥中索与梁、索与索之间的耦合振动问题,建立了斜拉桥的单梁-多索力学模型.考虑索的初始垂度引起的几何非线性因素的影响,将多索梁模型分段处理,基于索、梁经典的面内振动的微分方程,通过索、梁连接处的动态平衡条件,建立多索梁模型面内振动理论.以双索梁为例,应用分离变量法,结合边界条件,求解双索斜拉梁模型平面内自由振动的特征值问题.同时,建立双索梁的有限元模型,有限元所得结果与本文理论研究吻合良好.最后对CFRP索梁模型的各项相关重要参数进行分析,并将本文理论与课题组前期成果进行对比分析.研究表明,CFRP索能极大改善双索梁模型的基本动力学性能.增大拉索轴向刚度能明显提高模型的低阶频率,而梁弯曲刚度的提高对其高阶频率的提高比较明显.
Based on the classical dynamic theory of the cable and Euler beam as well as the dynamic equilibrium conditions at the joint of cable and beam, the in-plane vibration theory of a multiple cable-stayed beam was estab- lished, in order to study the couple vibration between cables and bridge deck. The combined effects of nonlinear terms due to the cable＇s geometry were considered, and the beam was separated into some segments. Using a double-cable-stayed beam model as an example, the variable separation approach and boundary conditions were considered to solve the eigenvalue problem of the in-plane free vibration of a double-cable-stayed beam structure. Meanwhile, a finite element model of the double-cable-stayed beam was also developed to verify the proposed the- ory and method, and a well match of the results between the two methods was obtained. Finally, the analysis about the key parameters was conducted, and a comparison was made between the early outcomes of project group and this paper. It shows that the CFRP cables can improve fundamental dynamic properties of the system than the traditional steel cables. Increasing the axial rigidity of cable and the flexural rigidity of the beam can, respective- ly, obviously enhance the lower and higher frequencies of the model.
出处
《动力学与控制学报》
2017年第6期494-504,共11页
Journal of Dynamics and Control
基金
国家自然科学基金项目(11572117
11502076)~~
关键词
多索梁
模态分析
CFRP索
频率
有限元
multiple cable-stayed beam, modal analysis, CFRP cable, frequency, finite element
