Debonding is one of the most important damage forms in fiber-reinforced composite structures. This work was devoted to the debonding damage detection of lap splice joints in carbon fiber reinforced plastic (CFRP) structures, which is based on guided ultrasonic wave signals captured by using fiber optic Doppler (FOD) sensor with spiral shape. Interferometers based on two types of laser sources, ...

A challenging goal of aircraft structural health monitoring (SHM) systems is to provide continuous assessment of structural integrity during flight. It is now widely recognized that variable environmental and operational conditions can compromise results and thus lead to erroneous maintenance and usage decisions. This issue is particularly evident for SHM systems utilizing ultrasonic guided wav...

Guided wave imaging with a distributed array of inexpensive transducers offers a fast and cost-efficient means for damage detection and localization in plate-like structures such as aircraft and spacecraft skins. As such, this technology is a natural choice for inclusion in condition-based maintenance and integrated structural health management programs. One of the implementation challenges res...

Scattering of ultrasonic waves in polycrystals with texture is studied in this article. The attenuations of the three wave modes are determined as a function of dimensionless frequency and propagation direction, respectively, for given orientation distribution coefficients (ODCs). The calculation is done in the case of a statistically orthorhombic sample made up of cubic crystallites. The wave ...

Ultrasonic testing (UT) has been used for nondestructive evaluation (NDE) of materials for more than half a century. A number of NDE techniques have been developed and specifi standards have been created for the UT applications in different areas of engineering. UT has two main goals related to inspection of solid objects, firstl , detection and characterization of material discontinuities (fl ...

Particles accumulated in a coupled acoustic-gravity field, in which the base-material of a particle determines the equilibrium aggregation positions, are eluted from a separation channel by an orthogonal laminar flow. Elution times are controllable by changing the intensity and frequency of the ultrasonic waves.

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...

In this paper we present a new digital ultrasonic instrument for nondestructive inspection of rock bolts using guided waves. The Rock Bolt Tester (RBT) instrument applies long-range ultrasound to investigate bolt’s status, especially its grouting condition. RBT features an application tailored ultrasound probe that transmits high-energy, low frequency (below 100kHz) guided waves and is capable ...

Carbon fibre composite laminates are increasingly being used for aerospace structures due to their low weight and improved mechanical performance. Impact damage can cause delaminations below the visible surface of structure limited interlaminar strength. Guided ultrasonic waves detect characterize in laminates. The scattering A0 Lamb wave mode at an artificial delamination, located asymmetric d...