Ultrasonic impact treatment for life extension of bridges with cracked and crack susceptible welded details

摘要

This paper assesses the effectiveness of ultrasonic impact treatment (UIT) on in-service bridge members. It presents the results of five years of acoustic emission (AE) monitoring of fatigue crack activity, both before and after UIT, at a large number of locations on a heavily loaded, 30-year-old railway bridge with both cracked and crack susceptible welded details. Positive results were obtained in treating details both with and without active fatigue cracks, however additional research is needed to determine the long term effectiveness of UIT as well as to develop an optimum repair and treatment protocol for details with existing cracks. This study is summarized in the following two pages.