Experimental Investigation on the Detection of Multiple Surface Cracks Using Vibrothermography with a Low-Power Piezoceramic Actuator

Abstract

Vibrothermography often employs a high-power actuator to generate heat on a specimen to reveal damage, however, the high-power actuator brings inconvenience to the application and possibly introduces additional damage to the inspected objects. This study uses a low-power piezoceramic transducer as the actuator of vibrothermography and explores its ability to detect multiple surface cracks in a metal part. Experiments were conducted on a thin aluminum beam with three cracks in different orientations. Detailed analyses of both thermograms and temperature data are presented to validate the proposed vibrothermography method. To further investigate the performance of the proposed vibrothermography method, we experimentally studied the effects of several critical factors, including the amplitude of excitation signal, specimen constraints, relative position between the transducer and cracks (the transducer is mounted on the same or the opposite side with the cracks). The results demonstrate that all cracks can be detected conveniently and simultaneously by using the proposed low-power vibrothermography. We also found that the magnitude of excitation signal and the specimen constraints have a great influence on detection results. Combined with effective data processing methods, such as Fourier transformation employed in this study, the proposed method provides a promising potential to detect multiple cracks on a metal surface in a safe and effective manner.

Feasibility Study of Real-Time Monitoring of Pin Connection Wear Using Acoustic Emission

“…Therefore, an effective nondestructive method for monitoring the health of pin connections in real time is necessary. With the recent advances in structural health monitoring (SHM) [2][3][4][5][6][7][8] and nondestructive evaluation (NDE) [9,10], many monitoring and evaluation methods, such as modal characteristics-based methods [11][12][13], active sensing [14][15][16][17][18][19][20], electromechanical impedance [21][22][23][24][25], ultrasonic guided wave [26], active thermography [26][27][28] and vibrothermography [29,30], among others, are available. Among them, acoustic emission technique [31][32][33][34][35][36][37] is an effective nondestructive technique that can characterize the wear process [38,39], and it has been widely used in civil engineering [40][41][42][43], mechanical engineering [44][45]…”

Measurement of Temperature of the Core of Concrete during Progressive Compressive Loading using Temperature Sensors

“…When mechanical vibrations are introduced into a friction and consequent deformation are induced and heat will be released which can be read by using infrared camera to detect the defects [7]. Extensive studies have been conducted related to long term temperature monitoring of concrete structures.…”

A New Grating Thermography for Nondestructive Detection of Cracks in Coatings: Fundamental Principle

“…Although the previous infrared thermal wave methods are efficient for horizontal cracks, most of them are invalid or insensitive to the vertical cracks because the propagation of thermal waves is parallel to the vertical cracks and thus is not affected by the vertical cracks. Recently, some other emerging infrared thermal wave methods, such as vibrothermography [19] and laser-line (or laser-spot) thermography [20][21][22][23], have been developed and used to detect vertical cracks. The vibrothermography method uses a specific acoustic excitation source to produce mechanical vibration inside the structure, and the cracks produce energy depletion and release heat, which eventually causes the rise of local temperature.…”