Crack height measurement — an evaluation of the accuracy of ultrasonic timing methods

Ultrasonic sizing of short surface cracks

“…Date et al [5] characterized slots down to 0.8 mm deep using the so-called time-of-flight (TOF) method with a mean error of 50 lm. This ultrasonic timing method allows for cracks which are large as compared to the wavelength to be assessed.…”

Estimation of Surface Crack Depth using Rayleigh Waves by Electromagnetic Acoustic Transducers

“…3, 8 In time domain, the propagating time of a surface wave along the crack's cliffs can be measured to estimate the extent of crack penetration. 9,10 It is an effective approach for depth characterization when the depth is greater than 0.8λ, in which the λ is the corresponding wavelength.…”

“…9,10 It is an effective approach for depth characterization when the depth is greater than 0.8λ, in which the λ is the corresponding wavelength. Date 8 employed the surface wave transmission method to measure the crack depth to a scale as small as 0.82 mm with a mean error of 0.01 mm using a 5 MHz probe. Similarly, Baby 11 employed time-of-flight diffraction to estimate crack depth in the range of 1.68-19.04 mm with excellent accuracy by using 4 MHz angle beam probes.…”

Measurement of Potential Drop Distribution by Scanning the Closely Coupled Probes Sensor for Sensitive NDE of Shallow Surface Cracks

“…Nondestructive evaluation (NDE) of cracks is needed for integrity assessment of structures based on fracture mechanics, and many techniques, for example, the ultrasonic techniques, [1][2][3] the eddy current techniques, 4,5) the electric potential drop techniques, 4,[6][7][8][9][10][11][12] etc., have been reported for NDE of cracks. The electric potential drop techniques are basically classified into two categories-direct current method [6][7][8][9] and alternating current method, 4,[10][11][12] and have been widely used for materials evaluation as well as the quantitative NDE of cracks.…”