High-sensitivity wire breakage monitoring for FAST feed cabin drive wire ropes based on multiparameter fusion

Abstract

As a critical load-bearing component of the feed cabin in the Five-hundred-meter aperture spherical radio telescope (FAST), the steel wire rope plays a vital role in ensuring the safe and stable operation of the equipment. Consequently, wire breakage monitoring of steel wire ropes is of great significance for safeguarding the reliable service of FAST. Aiming at the inherent limitations of existing monitoring methods, such as insufficient sensitivity and poor anti-interference ability under complex operating conditions, this study proposes a multiparameter wire breakage identification strategy that integrates time-domain features, frequency-domain features, and optical fiber drift. Meanwhile, a high-sensitivity fiber Bragg grating acceleration sensor tailored for weak vibration monitoring is successfully developed. First, the mechanism of wire breakage in steel wire ropes is systematically investigated to clarify the characteristics of frequency and amplitude variations induced by wire breakage, and the sensor structure is optimized in a targeted manner. Finite element simulation and performance test results demonstrate that the proposed sensor achieves a sensitivity of 753.1 pm/g, with an operating frequency range of 0–20 Hz and a frequency monitoring error of less than 1%, which enables the effective capture of weak vibration signals generated by the fracture of a single steel wire. Second, indoor wire breakage tests are conducted to establish the quantitative discrimination criteria between wire breakage and strand breakage signals: the drift of wire breakage is ≤0.2 nm, while that of strand breakage is ≥3 nm. Finally, the proposed technical system is applied to the bending fatigue tests of six groups of FAST-driving steel wire ropes, and 20 effective wire breakage signals are successfully identified. This study provides a complete technical pathway for the health assessment of FAST-driving steel wire ropes and offers a valuable technical reference for the nondestructive monitoring of steel wire ropes in complex engineering equipment.