Mode shape–aided cable force determination using digital image correlation

Abstract

Assuming the distance between two nodal points of a specific cable vibration mode as the effective length of a pinned–pinned cable, mode shape–aided cable tension estimation methods are employed to estimate the cable force. This article proposes a framework based on digital image correlation technique for remote measurement of the dynamic displacement time history of cables in cable structures. Frequency domain decomposition technique is then used to extract the cable natural frequencies and mode shapes. Identified cable mode shapes are used along with a tensioned pinned–pinned cable model to estimate the cable force. Accuracy of the proposed methodology is investigated using the experimental data coming from a laboratory-scale test setup and hanger cables of a real-world arch bridge.