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This paper focus on parameter identification of the main cables of cable suspension structures. Based on the dynamic stiffness theory, an inverse analysis characteristic function (IAC function) for identifying the main cable parameters (such as cable tension, moment of inertia, cable length, and mass per unit length) is established. This function allows for the consideration of cable flexural rigidity, sag, inclination, and additional lumped masses sustained by the suspender. The effects of the cable tension and moment of inertia on the IAC function are investigated via a numerical method. On this basis, a method for identifying the two parameters based on the peak-ridges of the IAC function is proposed. The method comprehensively utilizes measured multimode frequencies. It is unnecessary to determine the fundamental frequency and frequency order. A 20-m real cable test with suspended lumped masses is conducted to verify the correctness of the proposed methods. With the increase in the weight of suspended lumped masses, the advantages of the proposed method are more obvious. For operational cable tension less than 50% of the cable breaking tension, the cable moment of inertia is less affected by suspended lumped masses. [ABSTRACT FROM AUTHOR]

• A cable inverse-analysis characteristic function. • A parameter identification method based on the H-I ridges of characteristic function. • Identify cable force and bending stiffness simultaneously. • Short cables should consider bending stiffness, while long cables is negligible. • Short cables are more sensitive to cable length errors than long cables. • Bending stiffness of cables is variation with tension force with the same cables. Parameter identification of cables in the operation period is a significant issue related to the state of serviceability and safety evaluation of cables. A generalized characteristic function is established based on the dynamic stiffness theory to identify cable parameters in the study. The characteristic function exhibits an analytical form. The function relatively fits actual engineering cables due to comprehensively considering cable bending stiffness, sag, inclination, etc., and thus it is a relatively accurate inverse-analysis model of cable parameters. The variation of bending stiffness and cable force with different geometric parameters and the influence of geometric parameters on the identification accuracy of the two parameters are investigated based on numerical analysis. And a parameter identification method based on the H-I ridges of inverse-analysis characteristic function is proposed. The proposed method identifies cable parameters using the multi-order frequencies of cables simultaneously, and the order of modal frequencies and the fundamental or lower-order frequency are not required in the application of the proposed method. Finally, the results of tension tests on two real cables with lengths of 20 m and 168 m verify the applicability of the inverse-analysis characteristic function and the parameter identification method proposed in the study. [ABSTRACT FROM AUTHOR]

• Propose a tri-segment suspender dynamic model. • Propose an accurate identification method of suspender tension. • Propose a practical formula method for the convenience of engineering use. • The anchorage zone have significant effect on suspender dynamic characteristic. • For short suspenders, the effect of suspender anchorage zone is more prominent. Suspenders are main transmission force and load-bearing components of arch bridges and suspension bridges. The identification of suspender tension in service period is significantly to the normal service state and safety evaluation of structures. Based on the dynamic stiffness theory, this study establishes a tri-segment suspender dynamic model considering the effect of suspender anchorage zone. According to this model, an inverse-analysis characteristic function is established. On this basis, an accurate identification method by two optimization models is proposed, which are solved by the particle swarm optimization (PSO) algorithm, thus realizing the identification of suspender tension. Compared with the identification method of suspender tension based on the uniform equal-section dynamic model, the accuracy of the proposed model is higher. By fitting the data pairs of the suspender tension and frequency generated by the tri-segment suspender dynamic model, a practical formula method of suspender tension is also proposed, which is convenient for engineering use. By modifying the conventional cable tension formula, the practical formula method improves the identification accuracy of suspender tension, especially for short cables. Through a 20 m real cable test, it is proved that the two suspender tension identification methods (the accurate identification method and the practical method) proposed in this study have high identification accuracy and stability. [ABSTRACT FROM AUTHOR]