利用达朗伯原理建立了斜拉索风雨振连续体理论模型,实现了比截断模型能更好地体现连续体斜拉索完整的动力学特性.利用奇异性理论,对系统关于Z2对称的余维一分岔问题进行了分析,建立了分岔参数与物理参数的对应关系,得到了转迁集和分岔图,同时对平衡点附近的稳定性进行了讨论.从而有利于进一步开展斜拉索风雨振分岔行为的分析,为斜拉索桥的抗风雨振设计提供理论依据,便于拓展和应用到实际工程中.
The model of rain-wind-induced vibration of continuous stay cable is built on the basis of the dAlembert principle. This model can describe the dynamic characteristics of continuous stay cable better than the truncated model. By analyzing the static bifurcation behaviors according to the singularity theory,we describe the bifurcation problem as a one-codimensional unfolding with Z2 symmetry. The transition set and bifurcation diagrams for the singularity are presented,while the stability of the zero solution is studied using the eigenvalues in various parameter regions. The corresponding relationship between the unfolding parameters and the physical parameters will facilitates further analysis of the bifurcation behaviors of the stay cable,and it also provides theoretical basis for the design of cable stayed bridge. Meanwhile,it is helpful to the development and application of the engineering projects.