Date of Award
Master of Science (MS)
There has been an ongoing study conducted by Marquette University and supported by the Wisconsin Highway Research Program that is seeking to understand the risk of fatigue-induced fracture in the connections of mast-arm sign support structures. This study has been brought on by recent problems encountered with the connections contained in, and the in-service performance of, several cantilevered mast-arm sign support structures. A resulting recommendation of phase one in this effort was to monitoring an in-service cantilevered mast-arm sign support structure.
The health monitoring system developed in this thesis effort includes a grouping of strain gages (full-bridge arrangements) positioned around the perimeter of the mast-arm tube to monitor wind-induced strain near the mast-arm connection weld toes. This data is automatically recorded (continuously) using the data acquisition system designed and the software developed. Wind speed and direction is simultaneously read through an anemometer, synched to the strain data being acquired, and stored within the DAQ system using the software developed in this thesis. Finally, the thesis includes development of algorithms for synthesizing the data for later use in the WHRP project. The health-monitoring system designed and developed in this thesis will be left in place for future use in the WHRP research effort.