Abstract

Damage to conductors inside suspension clamps is extremely concealed, and failure to detect it effectively may lead to conductor breakage accidents. However, the engineering field still lacks reliable and efficient inspection methods. To address this, this paper proposes a strand-breakage damage detection method based on modal parameter identification under hammer impact excitation. A full-scale wire experiment is conducted to validate the detection method and investigate its influencing factors. The experiment shows that as the damage to the conductor inside the suspension clamp intensifies, the modal frequency of the conductor decreases, with a more pronounced decline in higher-order modes. Tension is positively correlated with the modal frequency of conductor vibration, and fluctuations in operating tension can cause drastic changes in modal frequency. Such variations can even exceed the modal frequency shift caused by structural damage. During the detection process, it is necessary to consider the impact of tension fluctuations on the detection results. The modal frequency of the conductor decreases slightly as the temperature rises. Specifically, for every 10 °C increase in temperature, the modal frequency of the conductor changes by less than 1%. The small fluctuations in modal frequency caused by temperature are much smaller than the frequency differences corresponding to adjacent degrees of damage. Therefore, there is no need to consider the influence of temperature during the actual detection process. This study verifies the feasibility of using modal identification under impact excitation for detecting strand breakage inside suspension clamps through experiments and analyzes the influencing factors of modal frequency, providing experimental support for the application of detection technology.

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