Infrared thermography (IRT) and acoustic emission (AE) are the two major nondestructive methodologies for evaluating damage in ceramic matrix composites (CMCs) for aerospace applications. The two techniques are applied herein to assess and monitor damage formation and evolution in a SiC-fiber reinforced CMC loaded under cyclic and fatigue loading. The paper explains how IRT and AE can be used f...

In ultrasonic nondestructive evaluation (NDE) of materials, pulse echo measurements are masked by the characteristics of the measuring instruments, the propagation paths taken by the ultrasonic pulses, and are corrupted by additive noise. Deconvolution operation seeks to undo these masking effects and extract the defect impulse response which is essential for identification. In this contributio...

Advances in magnetoresistive (MR) type sensors provide a new technique for nondestructive evaluation NDE of metal structures. GMR and GMI sensors provide high sensitivity and reduced size, with GMI sensors also adding capabilities of high frequency range of measurements. Being produced with thin film processing techniques, the manufacturing cost of these sensors is low. An example is considered...

The primary objective of this research program is to improve the characterization of small discontinuities (cracks, corrosion) using eddy current and ultrasonic methods for complex structures using computational methods in NDE. The research approach concerns the development and validation of efficient 3D models that accurately represent complex eddy current (EC) and ultrasonic (UD inspection pr...

In this paper, the inverse problem of reconstructing reflectivity function of a medium is examined within a blind deconvolution framework. The ultrasound pulse is estimated using higher-order statistics, and Wiener filter is used to obtain the ultrasonic reflectivity function through wavelet-based models. A new approach to the parameter estimation of the inverse filtering step is proposed in th...

Introduction Nondestructive testing (NDT) of structures and mechanical parts is increasingly receiving attention as the need to monitor the health of aging infrastructure and quality controls on the manufacturing of mechanical parts is becoming more apparent. NDT is defined as using various tools, whether they be acoustic, electromagnetic, or thermally based, to inspect the structural integrity...

The influence of corrosion on ultrasonic and electromagnetic nondestructive evaluation results has been simulated for 2-layer aluminum aircraft fuselage. Simulations have been performed with respect to ultrasonic time-of-flight measurements aiming on the detection of corrosion at the backwall of the first aluminum layer. Calculations of the eddy current probe response have been performed, where...

INTRODUCTION Resonance modes are intrinsic characteristics of objects when excited at those frequencies. Probing the resonance signatures can reveal useful information about material composition, geometry, presence of defects, and other characteristics of the object under test. Vibration spectra can be measured remotely with high degree of sensitivity using a millimeter wave (mmW) Doppler senso...

Abstract—Non contact evaluation of the thickness of paint coatings can be attempted by different destructive and nondestructive methods such as cross-section microscopy, gravimetric mass measurement, magnetic gauges, Eddy current, ultrasound or terahertz. Infrared thermography is a nondestructive and non-invasive method that can be envisaged as a useful tool to measure the surface thickness var...

The field of Computerized Tomography (CT) has revolutionized medical imaging and has been applied to the diverse fields of radio astronomy, electron microscopy, geophysics, stress analysis, radar, and nondestructive testing. Computer simulation has played an integral role in the development of CT systems and algorithms. This article provides an overview of CT and the tools used to model and sim...