Study of Monitoring Thermal Stresses in Continuously Welded Rails with L_CR Wave

An automatic NDT system for longitudinal thermal stresses in continuously welded rails with LCR wave, which is based on acoustoelastic theory, is described in this paper. The working principles of ultrasonic probehead and the LCR wave flight-time measured unit in the system are also introduced. In order to achieve the demands of railway, the linearity and the influence of temperature to system program is cousidered.