ABSTRACT
This paper proposed an approach transforms the cable force estimation problem from the common procedure of constructing and solving the equation of motion of the cable to a simpler problem of finding the modal nodes of its mode shapes. Digital image correlation is employed to capture the dynamic displacement of the point of interested on the surface of the measured cable under ambient vibration by matching the corresponding image sub-regions before and after the deformation. The frequency domain decomposition (FDD) approach is then utilized for modal identification from the measured displacements of the cable. According to the obtained modal identification results, the cable segment between any two modal nodes is selected to establish the equivalent tensioned beam model with two pinned ends, from which the cable force can be estimated. The laboratory test proved that the integrated approach has good applicability in practical engineering.
