Abstract: The accuracy of the frequency response measurement obtained using impact excitation and a Fast Fourier Transform based spectrum analyzer has been investigated. It has been shown that with impact ...

Abstract: The susceptibility to bias error of two methods for computing transfer (frequency response) functions from spectra produced by FFT-based analyzers using random excitation has been investigated. ...

Abstract: The changes in the natural frequencies of a beam produced by cracks have been compared with those caused by slots of the same depth and different widths. It has been shown both theoretically ...

Abstract: The use of a Nyquist plot of the H2 (Syy /Sxy *) frequency response function estimates produced by an FFT based spectrum analyzer with random excitation to obtain modal amplitudes and hence ...

Abstract: The dispersion relationships of a system comprising a circular bar imbedded in a solid medium having a lower acoustic impedance than the bar have been predicted. A generic study of such systems ...

Abstract: There is currently a need to improve the nondestructive testing techniques that are used to inspect grouted steel reinforcing tendons, anchors, and rock bolts for corrosion and fracture. A method of inspection using guided ...

Abstract: The reflection of the L(0, 2), axially symmetric guided elastic wave from notches in pipes is examined, using laboratory experiments and finite element simulations. The results show that the ...

Abstract: A study of the reflection of mode-converted guided waves from notches in pipes has been carried out. Measurements were made on a 76-mm bore diameter (nominal 3-inch), 5.5-mm wall thickness ...

Abstract: The practical testing of pipes in a pipe network has shown that there are issues concerning the propagation of ultrasonic guided waves through bends. It is therefore desirable to improve the ...