Initial Data Analysis of a Structural Health Monitoring System for Carbon Fiber Composite Strands in a Cable Stayed Bridge

摘要

The Penobscot Narrows cable stayed bridge design implemented in Prospect, Maine presented an opportunity to install Carbon Fiber Composite Cable (CFCC) strands as a test case for these advanced structural materials. The unique bridge design allows for convenient removal and replacement of the individual cable strands at each of the cable stays. Since the long-term response of the CFCC strands was of vital concern, a multifaceted structural monitoring system was incorporated during the cable installation. A brief description of the instrumentation used and a preliminary data analysis of the results recorded to date are presented in this paper. The multifaceted monitoring sensor system presented in this paper includes: conventional load cells for monitoring CFCC cable strand load at each anchorage location; Fiber Optic Strain (FOS) sensors to monitor CFCC strand strain; and temperature sensors to measure anchorage and ambient temperatures to account for CTE effects due to the various materials used for the cables, anchorage frame, and instrumentation. Upon completion of the instrumentation installation, a set of data were recorded from all sensors to use as the baseline from which all future measurements were referenced to. The goal of the analysis was to correlate the loads and strains in the cables to the temperature fluctuations. Analysis of periodic and continuous monitoring data recorded to date, including a comparison with the baseline data, is presented.