An experimental study of cable tension identification based on measurements of mode shapes

Cable tension identification based on mode shapes extracted from vibration measurements is a relatively new method. In this method, the cable is equivalent to a beam model hinged at its ends and under axial tension with an unknown length to eliminate the effects of boundary conditions. This study focuses on the influences of sensor arrangement in the measurements on the accuracy of the tension identification. For this purpose, full-scale cable experiments have been carried out, where a number of sensors were attached to the cable to record cable acceleration during artificial excitation. The eigenvalue realization algorithm (ERA) has then been applied to identify the mode shapes and frequencies of the cables from the multiple acceleration measurements. The effects of different sensor arrangement schemes and cable tension identification method based on higher- order modes are compared and discussed.