An apparent increase in the detectability of certain flaws results when the ultrasonic inspection beam was oriented off the longitudinal axis of railroad rail. Here, artificial reflectors were used to better define the extent of material "seen" by inspection beams, and determine how surface curvature might affect the inspection. Presumably, such information could be useful for suggesting optimu...

This paper reports the simulation of phased array ultrasonic wave propagation using Finite Difference Time Domain (FDTD) method to image crack like defects in Aluminum Blocks and Stainless Steel elbow sections. Inclined crack like defects have been considered for the simulation. Experiments were also performed on an Aluminum block with inclined embedded cracks various sizes in order to validate...

In a typical ultrasonic material characterization system, the output voltage of the transducer is recorded as a function of the relative position of the transducer and the specimen. The velocity and attenuation of the leaky surface acoustic waves and the reflectance function for the immersion liquid–specimen interface can be obtained from the recorded data. The experimental arrangements with lo...

In this work, low temperature deposition of ceramics, in combination with micromachining techniques have been used to fabricate a kerfed, annular–array, high–frequency, micro ultrasonic transducer (with seven elements). This transducer was based on PZT thick film and operated in thickness mode. The 27 μm thick PZT film was fabricated using a low temperature (720 oC) composite sol-gel ceramic (s...

In order to improve the accuracy of ultrasonic phased array focusing time delay, analyzing the original interpolation Cascade-Integrator-Comb (CIC) filter, an 8× interpolation CIC filter parallel algorithm was proposed, so that interpolation and multichannel decomposition can simultaneously process. Moreover, we summarized the general formula of arbitrary multiple interpolation CIC filter paral...

A technique is developed to simultaneously acquire ultrasound and photoacoustic (PA) images based on a linear transducer array. The system uses conventional ultrasound for rapid identification of potential targets. After a target is identified, the ultrasound echo and PA signals can be simultaneously obtained with optimized excitation and a signal collection sequence. The corresponding ultrasou...