Ultrasonic transducer array for structural intensity measurements

Measurement of structural intensity, which is a vector quantity defined as an energy flow of vibration per unit area and is calculated from vibration velocity distribution, is a key technique for radiation noise reduction and vibration control. An ultrasonic Doppler vibrometer array is proposed for structural intensity measurement. A useful large array probe can be constructed. Since the ultrasonic system is much cheaper than an optical one, and has no loading effect on specimens during measurement, in constant with conventional methods that use an accelerometer and a strain gauge, a system for 1-dimensional measurements is made which is composed of ultrasonic transducers and an FM demodulator. The validity of the proposed system is demonstrated experimentally by the 1-dimensional structural intensity measurement of a beam.