Development of a Cable Robot and Measurement of Stay Cable Roundness
-
2024-03-01
Details:
-
Creators:
-
Corporate Creators:
-
Corporate Contributors:
-
Subject/TRT Terms:
-
Publication/ Report Number:
-
Resource Type:
-
Geographical Coverage:
-
Edition:Final Report
-
Contracting Officer:
-
Corporate Publisher:
-
Abstract:A previous study involving a wind tunnel investigation of a stay cable found that rotating the cable along its longitudinal axis changed its wind-induced response, revealing that the slight eccentricity of the cross-sectional shape was influencing the response. The study speculates that surface deformation could have caused nonsymmetrical separation of the boundary layer on either side of the cable, inducing across-wind forces and other instabilities. Although using high-density polyethylene pipe is an extremely popular method to shield a stay cable’s steel strands from environmental impacts, not much is known about its exact geometry other than a few simple characteristics such as nominal diameter and pipe thickness. While the cross-sectional shape is often assumed to be circular, the actual shapes found in the field are generally unknown and could be affected by various factors, including manufacturing, storage, and sag-deformations over time. To study these shapes, an FHWA team built a cable robot capable of climbing stay cables and taking cross-sectional measurements of the pipes in the field. This report discusses the design process for developing the robot, including automating and calibrating the robot and analyzing the resulting field data. The team selected and visited 11 bridge sites during testing, and the results are presented and discussed, including visualizations of the cable shapes. Overall, 67 individual cables were tested and over 1,700 roundness measurements were recorded. Averaged eccentricity values ranged from 0.8–5.2 percent per cable.
-
Format:
-
Funding:
-
Collection(s):
-
Main Document Checksum:
-
Download URL:
-
File Type: