DEVICE FOR MEASURING INITIAL DAMAGE TO PRESTRESSED CONCRETE BEAM BY NONLINEAR RESONANT ULTRASONIC METHOD

摘要

Disclosed is a device for measuring initial damage to a prestressed concrete beam, the device comprising: a control unit; a signal generator receiving a signal from the control unit to generate an input signal; a signal amplifier receiving the input signal from the signal generator to amplify it; a signal converter, disposed on the prestressed concrete beam, to convert the amplified signal received from the signal amplifier into an ultrasonic signal and send the ultrasonic signal to the prestressed concrete beam; a signal receiver, disposed on the prestressed concrete beam, to receive the ultrasonic signal passing the prestressed concrete beam; and a digital converter receiving the ultrasonic signal output from the signal receiver to convert it into a digital signal. The control unit receives the digital signal converted by the digital converter, and calculates a resonant frequency from the digital signal and the signal sent from the signal generator to obtain a nonlinear factor. Therefore, it is possible to evaluate the beam with high sensitivity.;COPYRIGHT KIPO 2018