Comparison of Sensor Arrangement in Vibration-Based Tension Force Determination of Fixed-End Stayed Cable

Measurement of cable performance is necessary to monitor a cable-based structure such as a cable-stayed bridge. Non-destructive evaluation vibration-based approach has been widely used to evaluate the cable force by installing sensors on the targeted element. This research aims to study the effect of vibration sensor deployment along the cable in predicting the tension. The distances between the sensor used in this study are 5% and 10% of the total length for Case 1 and Case 2, respectively. Numerical exploration of cable vibration is simulated under random excitation. Five vibration sensors are applied along the cable to record the signal with two cases of sensor arrangements. In extracting the dynamical system properties, covariance driven stochastic subspace identification is implemented. Five pairs of frequency and effective length are obtained from signal analysis in Case 1, while eight pairs are gathered in Case 2. Tension predictions are figured out by applying these two dynamic parameters to an existing formula. The results show that cable force estimation in Case 2 gives better performance than in Case 1. Comparative studies of these two cases are discussed and presented in this paper.