Tension Identification Of Cable With Two Intermediate Supports

For the existing bridge cable structures such as stay cable of cable-stayed bridge,tie bar of tied arch bridge, and external prestressed tendons, the conventional stringvibration theory can not be used for cable force measurement of such cable structurewith complex boundary condition of intermediate supports and multiple dampers. Forthe exiting cable-stayed bridge, the dampers are general installed near the deck andpylon anchorage zones to resist the wind-induced vibration.The study place emphaseson the tension force identification of the cable with two intermediate supports. Thethesis is organized as follow:(1) Analytical method is employed to establish the frequency equation of thecable with two dampers. The asymptotic solution method and iteration method wereconducted to attain the non-dimensional frequency eigenvalue equation and theexplicit expression of the cable tension.(2) The viscous damper, shearing-type HDR (High damping rubber) damper andcompression-type HDR damper are modeled to investigate the effect of damperparameters, supporting stiffness, and damper position on the vibration characteristicsof the cable, and conduct an error analysis on the asymptotic solution.(3) The dynamic stiffness matrix method is based on the theory of finite element.The cable is divided by intermediate supports into single element, every element isconnected at the intermediate supporting position. The dynarmic stiffnesscontributions from the two elements on each side of the intermediate supportingposition are then assembled into global dynamic stiffness matrices for the cases ofclamped and pinned supports, according to the condition of deformationcompatibility.(4) The dynamic stiffness matrix method was presented to construct thefrequency equation for5typical cable vibration models Both the particle swarmoptimization (PSO) method and the iteration method were employed for solution ofthe frequency equation. The proposed method can fully consider the effect of bendingstiffness, end condition, and supporting stiffness on the identification accuracy.(5) The identification accuracies of the proposed methods were analyzed bycomparing with the solutions of ANSYS and the existence of classical solutions. Thedynamic tests on the Balihu bridge and Haiyin bridge verified the effectiveness of the methods.