Application of Electronic Speckle Pattern Shearing Interferometry with High-Speed Camera in Vibration Analysis of Piezoelectric Transducer

Abstract

Electronic speckle pattern shearing interferometry, also known as shearography, is a highly sensitive technique that can measure the distribution of the displacement derivatives of the object surface. This method has also been used to describe the mode shapes of vibrating objects. In the current research, electronic speckle pattern shearing interferometry with high-speed camera was proposed for full-field measurement of the derivative of the vibration amplitude. One of the important limitations of time-average shearography is that this method is only able to provide the qualitative measurement of vibration amplitude. Stroboscopic shearography also has an inevitable limitation on the measurement of vibration amplitude at frequencies lower than 50[Formula: see text]Hz. To study the performance of shearography with high-speed camera, the research concerned the low-frequency vibration of a piezoelectric transducer during its operation. The proposed method overcomes the limitations of conventional shearography methods in quantitative measurement of vibration amplitude at low frequencies. Laser Doppler vibrometry (LDV) method was used to verify the measurement results of shearography with high-speed camera. The obtained results indicated good agreement between both shearography with high-speed camera and LDV methods. However, due to the rigid body motion of the piezoelectric transducer, LDV results generally represented more values for the maximum amplitude.