斜拉桥多索-浅拱-弹性约束模型及面内自由振动

Elastically Constrained Multi-cable-stayed Shallow-arch Model in Cable-stayed Bridge and Its in-plane Free Vibration Research

考虑斜拉桥的初始构型和支座刚度,建立了竖向弹性约束下的多索-浅拱动力学模型.首先基于索和浅拱的经典动力学方程,将浅拱在索-拱耦合处分段,推导了竖向弹性约束多索-浅拱的面内自由振动理论.然后采用分离变量法对其面内特征值问题进行了求解.同时以双索-浅拱模型为例,建立了相应的有限元模型,并将论文方法算出的频率和模态与有限元结果进行对比,从而验证了论文方法和模型的正确性.最后,对竖向弹性约束双索-浅拱的动力学特性进行了系统的参数化分析.结果表明:竖向刚度对系统的动力学特性有着明显的影响.

Considering the initial configuration and support stiffness of cable-stayed bridge,the multi-cable-stayed shallow-arch model with vertical elastic constraints is established.Firstly,based on the classical dynamics equations of the cable and shallow arch,the theory of in-plane free vibration of the model is deduced by dividing the shallow arch into several segments at the cable-arch coupling points.Then,the double-cable-stayed shallow-arch model is taken as an example and its in-plane eigenvalue problem is solved by separation-of-variable method.At the same time,taking the double-cable-shallow arch model as an example,the corresponding finite element model is established.The frequencies and mode shapes calculated by the present method are compared with those obtained by finite element method,which verifies the correctness of the method and model in this paper.Finally,a systematic parametric analysis on the dynamics properties of the model is conducted.It is shown that the vertical stiffness has a significant effect on the dynamics properties of the system.