Research on the Dynamic Characteristics of Cables Considering the Constraints at Both Ends of the Cables

Abstract

Suspension bridges and arch bridges are important structural forms of bridges in which the cables are the main load-bearing members. The study of dynamic characteristics of the cable is of great significance to the design and operation and maintenance of suspension bridges and arch bridges. Firstly, this paper derives the cable frequency equation considering the bending stiffness under arbitrary boundary conditions from the dynamic stiffness method (DSM), and gives the calculation method of cable vibration modal frequency based on the W–W algorithm. Secondly, on this basis, the cable boundary condition coefficients and stiffness ratios are introduced to reflect the constraint strength of the main cable and stiffening beam on the cable, so as to study the influence law of these boundary conditions on the cable modal frequency, and then determine the actual cable boundary conditions of this kind of bridge. Finally, the boundary condition coefficients determined in this paper and the relevant parameters of the cables are inversely used to determine the boundary conditions of the actual bridge cables, and a simple method suitable for determining the boundary conditions of the cables in practical engineering is discussed, i.e., the theoretical basis for determining the boundary conditions of the cables through the relevant parameters of the cables, and the practical discussion of the theory is verified through the actual bridge cables. This study provides a reference for further theoretical analysis of cables, a theoretical basis for calculation of actual bridge cables, boundary conditions for in-depth study of dynamic characteristics of cables, and guides the design, operation, and maintenance of cables.