Comparative Study on Frequency-Based Cable Parameter Identification Algorithms

Frequency-based algorithms are prevalently used to estimate bridge cable tensions. However, for the non-negligible bending stiffness, the eigenproblem involves a cumbersome procedure of solving transcendental equations, which aroused various treatment skills for simplification or optimization, yielding diverse identification algorithms with different effectiveness, efficiency, and applicability that bring difficulties and confusion in making an appropriate choice for users. Therefore, it is necessary to systematically illustrate these algorithms’ intrinsic relations, differences, and application characteristics. A comprehensive comparative study on five representative algorithms, including analytical and empirical formulas and optimal algorithms, is carried out in this paper by parallelly identifying cable parameters on 24 real-life bridge cables worldwide available in the literature. Results show that: (i) Algorithms of empirical formulas are always based on the modified chord theory or tensioned-simply-supported beam model, resulting in the solution of two simultaneous equations by providing two measured frequencies in case of unknown bending stiffness. (ii) Proper identification procedure is significant in applicating an algorithm. (iii) The FROCPI algorithm is the simplest method with good consistency and broad applicability for long and short cables.