time-of-flight diffraction method (tofd) is an amplitude-independent sizing method which is based on the measurement of time-of-flight of defect tip diffracted waves. although tofd can measure through-wall length of defect accurately, this method is not capable of measuring horizontal defect size. in this paper, a new tofd method for evaluating horizontal planar defects is presented. the finite...

The embedded ultrasonic structural radar (EUSR) was developed based on phased array technology. It can interrogate large structural areas from a single location using ultrasonic guided Lamb and Rayleigh waves generated by tuned piezoelectric wafer active sensors (PWAS) that are permanently attached to the structure. This paper brings together several aspects of the implementation and applicatio...

In order to obtain the highest performances requested by the safety authorities for ultrasonic inspections, in terms of flaw characterization, the CEA (French Atomic Energy Commission) has developped the F.A.U.S.T. (Focusing Adaptive UltraSonic Tomography ) system, supported by the french Institute for Nuclear Protection and Safety (IPSN). This technique is based on phased array transducers dyn...

An optimization design method was proposed for linear phased array ultrasonic imaging testing. In the method, main lobe width and the amplitude ratio of side lobe to main lobe were served as optimization objectives to judge the testing precision of phased array beam directivity. The combination of element of width and inter-element space was served as optimize parameter for the optimization obj...

Relaxor-based ferroelectric single crystals Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) have drawn much attention in the ferroelectric field because of their excellent piezoelectric properties and high electromechanical coupling coefficients (d33~2000 pC/N, kt~60%) near the morphotropic phase boundary (MPB). Ternary Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) single crystals also possess outstan...

Air-coupled ultrasonic techniques are being increasingly used for material characterization, non-destructive evaluation of composite materials using guided waves as well as for distance measurements. Application of those techniques is mainly limited by the big losses of ultrasonic signals due to attenuation and mismatch of the acoustic impedances of ultrasonic transducers and air. One of the wa...

According to European Standard EN 1712 ultrasonic testing of thin-walled welded joints is mandatory for wall thicknesses of more than 8 mm only. Any thinner components do have to undergo X-ray inspection. Besides various advantages of X-ray testing viz. high sensitivity to smallest inclusions, high acceptance in the ship building sector and “automatic” documentation of inspection results, there...

Metal structures can fail because of fatigue crack propagation or because of section loss from corrosion. Regular inspection is required to intercept such failures, and in situ sensors would be a superior technology for that purpose. We have designed and fabricated arrays of MEMS capacitive diaphragm transducers and we report on their performance as pulse-echo detectors in direct contact with s...

Because of the need of rapid detection of internal defects and embedded object in concrete structures, a ultrasonic detecting method with linear array transducers is presented here, which is the high-resolution and efficient imaging technique for concrete materials by combining with synthetic aperture focusing technique (SAFT). At first, simulation data of array detection are processed to be am...