Vertical Vibrations of Suspension Bridges: A Review and a New Method

Suspension bridges offer an elegant and economical solution for bridging over long spans with resultant low material content and ease of construction. Classical analytical methods for the linear vertical vibrations of a suspension bridge usually ignores the flexibility of hangers and bending stiffness of the main cable, and the bending stiffness and mass of the stiffening girder are uniformly distributed to the main cable. However, results show that the flexibility of the hangers has a significant effect on higher-order modal frequencies and may loss some modal information when using the inextensible hanger assumption. In view of this, this paper developed a succinct and universal analytical method for vertical flexural vibration analysis of the suspension bridge, which truly considers the vertical support stiffness of each hanger for the first time. The comparison with finite element solutions and field measurement results shows that the calculation accuracy of the proposed method is significantly improved compared with the classical analytical method. The calculation error of this paper is basically below 5%, besides, the mode-missing problem existing in the classical analytical methods is well solved.