Magnetostriction Stress Measurement on Dynamic Stress of Bridges and Sensitivity Calibration of Steel Used for Bridges

—Applicability of Stress Measurement Technique Using Magnetostriction Effect to Welded Structures (Report 2)—

Abstract

On maintenance of structures, there is a strong need to know stress conditions of steel structure in use. Stress measuring technique using the magnetostriction effect utilizes magnetic field distortion by strain of steel itself. It has a possibility to measure stress already existed in structures beforehand, such as dead load stress or welding residual stress. We made an experimental study on dynamic stress measurement of steel bridges and calibration of magnetostriction sensitivity of the steel used for bridges. Following results were obtained. (1)By revised magnetostriction stress measuring equipment, dynamic stress fluctuations of steel bridges under real traffic were measured within the accuracy of 95%.
(2)Calibration procedures of magnetostriction sensitivity of steel used for bridges were proposed.