Temperature effect on cable frequencies and evaluation of cable corrosion

Abstract

Since cables are important to the structural safety of cable-stayed bridges, it is essential to identify and monitor cable forces throughout their design lives. Changes in temperature may also cause variations in cable forces. In structural health monitoring systems, the cable forces are often identified by analyzing the cable frequencies based on the cable vibration theory. Based on the structural health monitoring system of Hengfeng Road Bridge in Shanghai, China, the temperature-induced variations in cable frequencies are studied. A linear regression model has been developed to analyze the relationship between the cable frequencies and temperature measurements. Data analysis demonstrates that the measured cable frequencies and temperatures are highly correlated linearly. This paper also presents a theoretical investigation of the temperature-induced variations in cable frequencies, and proposes a method based on the mass variation of the cable to evaluate the possible corrosion of cable. © 2012 Taylor & Francis Group.