Frequency-Based Cable Tension Identification Using a Nonlinear Model with Complex Boundary Constraints

Accurate estimation of the cable force affects bridges’ long-term integrity and serviceability directly. The frequency method is often used for tension testing in bridge engineering. However, generally calculation formulae are based on “ideal hinge” or fixed” boundary conditions. inclination, bending stiffness, sag-extensibility not properly considered, which results non-negligible errors. A frequency-based precisely determining tensile a with unknown rotational support constraint stiffnesses at was proposed. nonlinear mathematical model vibration established. In addition to parameters such as sag, effects both ends were also considered. finite difference employed discretize solve mode equation vibration. sensitivity-updating algorithm applied that can identify simultaneously several system using multiorder measured natural frequencies. Calculation matrix eigenvalue derivatives key obtaining sensitivity matrix. Numerical examples indicated be efficiently multiple cable, including its tension, stiffnesses.