Ultrasonic Impact Treatment of Traffic Signal Mast Arm Welds

Ultrasonic Impact Treatment (UIT) has developed over the past few decades as a weld treatment with potential for great fatigue resistance enhancement. Prior research of traffic signal mast arm welds with UIT application indicates that UIT may significantly increase fatigue life of traffic signal structures. Currently UIT is being considered by the Texas Department of Transportation as part of the fabrication process of new traffic signal mast arms, as well as a potential retrofit for in-service traffic signal structures. This study was initiated to investigate UIT as a viable retrofit for in-service traffic signal structures, as well as to investigate aspects of UIT plication specific to Texas traffic signal mast arm welds.