| Advanced Nondestructive Evaluation (NDE) Sensor Modeling For Multisite Inspection |
Oct-2008 |
167 pages |
| Authors:
Zhiwei Zeng; Yiming Deng; Satish Udpa; R Bossi; B Koltenbah; L Udpa; Liu Xin; BOEING INFORMATION SPACE AND DEFENSE SYSTEMS SEATTLE WA
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 | The Advanced Nondestructive Evaluation (NDE) Sensor Modeling for Multisite Inspection program has developed finite element models (FEM) of electromagnetic NDE for optimizing the inspection of aging aircraft structure. The program found excellent correlation between magnetic field strengths predicted by FEM analysis and experimental values in fastened airframe structure configurations. Applying the FEM analysis to magnetoresistive (MR) sensors inspection problems then provided useful insights into the many parameter effects associated with ... |
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| Recent Advances in Remote Field Eddy Current NDE Techniques and Their Applications in Detection, Characterization, and Monitoring of Deeply Hidden Corrosion in Aircraft Structures, |
1999 |
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| Authors:
Yushi Sun; Tianhe Ouyang; Satish Udpa
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 | The remote field eddy current (RFEC) technique is based on the RFEC phenomenon which is characterized by differences in the energy flow patterns in the near and remote field regions. The energy released by the probe excitation coil traverses the pipe wall twice before reaching the pickup coil. The RFEC technique, currently used in metallic tube inspection, is therefore characterized by its equal sensitivity to a flaw irrespective to its ... |
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| Integrating a Stress Corrosion Crack Model into Finite Element Electromagnetic NDT Code, |
1998 |
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| Authors:
Gregory Kobidze; William Lord; Satish Udpa
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| This paper describes a stress corrosion crack model and its implementation in a finite element code for simulation of magnetic flux leakage inspection. The objectives of this work are: a) model a stress corrosion crack by the variations of electromagnetic properties of materials, b) use special elements for crack description in the finite element simulations, thus avoiding the necessity of dense mesh discretization, c) find appropriate shape functions, that allow ... |
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| A Modified Differental Pickup Reflection Probe, |
1998 |
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| Authors:
Sarit Sharma; Lalita Udpa; Yushi Sun; Satish Udpa
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| In this study and eddy current inspection of multi-klayered structures in aircrafts, the detection of flaws in the subsurface layers is a significant challenge and requires very sensitive probes. |
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| Finite Element Modeling of Eddy Current Probes for Edge Effect Reduction, |
1997 |
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| Authors:
Sait Sharma; Ibrahim Elshafiey; Lalita Udpa; Satish Udpa
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| This paper investigates the design of a new eddy current probe for eliminating the edge effect. A simple method to focus the field is devised using a combination of two coils. The total field distribution is controlled by choosing the coil geometry and coil currents appropriately. Both the magnitude and phase of the currents in the two coils are varied in order to obtain the desired flux pattern. The efficiency ... |
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| Classification of Ultrasonic Weld Inspection Data Using Principal Component Analysis, |
1997 |
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| Authors:
Sangmin Bae; Lalita Udpa; Satish Udpa; Tom Taylor
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| This paper presents a new defect classification method intended to reduce the human variability in ultrasonic weld inspection. The classification technique is based upon principal component analysis (PCA). The technique is applied in this work to provide features in a reduced dimensional feature space for ultrasonic signals. |
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| Texture Analysis Using Multiresolution Analysis for Ultrasound Tissue Characterization, |
1997 |
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| Authors:
Nam-Deuk Kim; Viren Amin; Doyle Wilson; Gene Rouse; Satish Udpa
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| In this study, we will discuss a method for estimating quality attributes (such as marbling) in live animals. This relation reflects the subjectiveness of marbling grades and indicates the need for an objective method of characterizing IMFAT or marbling. |
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| Magnetic Particle Inspection Simulation Model, |
1996 |
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| Authors:
Atul Athavale; Lalita Udpa; Satish Udpa; Zuorong Zhang
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| The Magnetic Particle Inspection (MPI) method is generally used to detect surface and near surface flaws. In a MPI test, a ferromagnetic specimen in unmagnetized state is sprayed with magnetic particles in an aerosoft suspension. The particles are generally ferromagnetic oxides coated with fluorescent pigments and the suspension is a petroleum distillate of low viscosity. The specimen is then magnetized. In the presence of a flaw transverse to the direction ... |
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| Registration Issues in the Fusion of Eddy Current and Ultrasound NDE Data Using Q-Transforms, |
1996 |
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| Authors:
Kai Sun; Satish Udpa; Lalita Udpa; Tianji Xue; William Lord
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| Data fusion methods are finding increasing application in nondestructive evaluation (NDE) for enhancing the reliability of inspection. These techniques typically combine information from two or more NDE modalities to improve the probability of detecting flaws and enhance specimen characterization results. Eddy current methods rely on diffusion for propagating energy. Ultrasonic methods, in contrast, rely on wave propagation. Consequently, the two tests rely on different material/energy interaction processes and can potentially ... |
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| Probe Design for Edge Effect Reduction in Eddy Current Inspection, |
1996 |
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| Authors:
Sarit Sharma; Ibrahim Elsafiey; Lalita Udpa; Satish Udpa
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| Eddy current methods are used extensively in the nondestructive testing (NDT) of aircraft structures and parts. One of the challenging problems in the inspection of aircraft structures is the detection of flaws in multilayer geometries in the vicinity of edges. Very often the large contribution to the signal from the edges mask the information related to the defects. The design of new eddy current probes for reducing edge effects is ... |
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| Numerical Modeling and Experimental Study of Motion Induced Remote Field Curent Effect and Its Application to Online Inspection and Quality Examination of Rolling Metallic Strips, |
MARC |
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| Authors:
Yushi Sun; Satish Udpa; W. Lord; L. Udpa
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| Currently, rolled metallic strips and sheets are inspected off-line, which is costly, time consuming and not ideal for quality control. A well designed online diagnostic and control system for metal rolling process may largely reduce cost, improve quality, and hence enhance competitiveness of the product. The overall objective of this paper is to study a new nondestructive measurement system for on-line diagnostics and control of metallic rolling process using motion-induced ... |
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