Experimental Study of Cable Tension Force Identification Method Based on Effective Vibration Length

Accurate identification of cable tension is crucial for the structural health monitoring of cable-stayed bridges. Traditional frequency-based methods often exhibit significant errors when applied to short cables due to complex boundary conditions induced by damping or guiding devices. To address this issue, this study experimentally verifies three improved methods for cable tension force identification based on effective vibration length (Methods E0, E1, and E2). A 6-meter short cable test was conducted, considering factors such as guiding device configurations, mass block additions, and accelerometer layouts. The results demonstrate that Methods E1 and E2 exhibit higher robustness compared to the conventional Method E0, achieving relative errors below 5% in most cases. Additionally, sensor installation errors and dense accelerometer layouts were identified as critical factors influencing identification accuracy. The findings provide practical insights for enhancing cable tension measurement in real applications, particularly under complex boundary conditions.