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Nondestructive Evaluation

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Full-Text Articles in Engineering

Fusion Of Microwave And Eddy Current Data For A Multi-Modal Approach In Evaluating Corrosion Under Paint And In Lap Joints, Kapil Gupta, Mohammad Tayeb Ahmad Ghasr, Sergey Kharkovsky, R. Zoughi, R. Joe Stanley, Ajay Padwal, Matthew O'Keefe, Donald D. Palmer, J. Blackshire, Gary Steffes, N. Wood Sep 2018

Fusion Of Microwave And Eddy Current Data For A Multi-Modal Approach In Evaluating Corrosion Under Paint And In Lap Joints, Kapil Gupta, Mohammad Tayeb Ahmad Ghasr, Sergey Kharkovsky, R. Zoughi, R. Joe Stanley, Ajay Padwal, Matthew O'Keefe, Donald D. Palmer, J. Blackshire, Gary Steffes, N. Wood

Reza Zoughi

Critical aircraft structures are susceptible to hidden corrosion. Find-it and fix-it approaches are inefficient as it relates to managing the problems associated with corrosion. More comprehensive corrosion information may be obtained using data fusion from several detection and evaluation methods. To this end, microwave, conventional and pulsed eddy current data from a multi-layer corroded panel, representing an aircraft lap joint, are fused and used as inputs to a structural analysis model to obtain a comprehensive snapshot of the corroded environment. This paper presents the data fusion algorithm and the structural analysis model along with a discussion of the results.


Nondestructive Evaluation And In-Situ Monitoring For Metal Additive Manufacturing, Hossein Taheri Jan 2018

Nondestructive Evaluation And In-Situ Monitoring For Metal Additive Manufacturing, Hossein Taheri

Graduate Theses and Dissertations

Powder-based additive manufacturing (AM) technologies are seeing increased use, particularly because they give greatly enhanced design flexibility and can be used to form components that cannot be formed using subtractive manufacturing. There are fundamental differences in the morphology of additively manufactured materials, when compared with, for example castings or forgings. In all cases it is necessary to ensure that parts meet required quality standards and that “allowable” anomalies can be detected and characterized.

It is necessary to understanding the various types of manufacturing defects and their potential effects on the quality and performance of AM, and this is a topic ...


Material State Tracking By Nondestructive Evaluation Data, Elizabeth Dimmitt Gregory Jan 2016

Material State Tracking By Nondestructive Evaluation Data, Elizabeth Dimmitt Gregory

Graduate Theses and Dissertations

This thesis tackles the challenge of using nondestructive evaluation data as a sensor measurement input for a state estimation scheme in order to estimate the current state a part that is changing over time. This is made particularly challenging because of the multidisciplinary nature of the problem. The estimation solution incorporates work from statistics, computer vision, and the physics of nondestructive evaluation.

This thesis discusses the basis for spatio-temperal Kalman filtering and uses a simple version of spatio-temperal filtering to simulate material state tracking on composite spec- imens. The simulation illustrates that by using the algorithm presented here, even with ...


Phase I Inspection Of The Stay Cable System On The Us 231 William H. Natcher Bridge Over The Ohio River, Theodore Hopwood Ii, Sudhir Palle, Danny Wells, Bobby W. Meade, Jared Fairchild, Christopher Goff Jan 2016

Phase I Inspection Of The Stay Cable System On The Us 231 William H. Natcher Bridge Over The Ohio River, Theodore Hopwood Ii, Sudhir Palle, Danny Wells, Bobby W. Meade, Jared Fairchild, Christopher Goff

Kentucky Transportation Center Research Report

The US 231 Natcher Bridge was opened in 2002. By 2006 cracking was observed in the plastic piping that protected the stay cable strands from the environment at both the deck and tower anchorages. Over time the extent of cracking increased and an investigation was initiated to assess the types of deterioration impacting the cables, their causes and their impacts on the integrity of the stay cables.

From 2012-2015, a series of in-depth field inspections were performed using visual and nondestructive testing. Most of this work focused on the piping at the deck anchorages. The inspections disclosed voids in cable ...


Evaluation Of Some Parameters Influencing Vibrothermographic Crack Heating, Tyler Joseph Lesthaeghe Jan 2015

Evaluation Of Some Parameters Influencing Vibrothermographic Crack Heating, Tyler Joseph Lesthaeghe

Graduate Theses and Dissertations

Vibrothermography is a nondestructive testing technique that uses vibration-induced heating to locate cracks inside parts. Industrial application of vibrothermography has typically been limited due to a lack of complete understanding of the factors influencing vibrothermographic crack heating. In other words, in otherwise identical circumstances, some cracks heat differently. This thesis presents modified versions of three journal papers related to developing a predictive forward model of the vibrothermography process. The first paper discusses an empirical model for vibrothermographic crack heating, including factors for vibrational amplitude, crack mobility and crack closure. The paper provides details of the model and the data collection ...


Review Of Materials Property Data For Nondestructive Characterization Of Pipeline Materials, Lucinda Jeanette Smart Jan 2015

Review Of Materials Property Data For Nondestructive Characterization Of Pipeline Materials, Lucinda Jeanette Smart

Graduate Theses and Dissertations

The oil and gas industry relies on an aging infrastructure of pipeline for transportation and distribution of product; therefore, it is important to assess the condition of the pipeline, using accurate material and mechanical properties, to ensure failures are minimized. Nondestructive evaluation techniques are currently being used to assess pipeline, but necessary mechanical properties (yield strength, tensile strength, fracture toughness, and ductile-to-brittle transition temperature) are not yet able to be adequately characterized by these methods.

There are many issues to consider when addressing this problem. There is variability within the manufacturing processes due to simple inaccuracies in the processes themselves ...


Vibration Modeling For Vibrothermography, Jyani Somayajulu Vaddi Jan 2015

Vibration Modeling For Vibrothermography, Jyani Somayajulu Vaddi

Graduate Theses and Dissertations

Vibrothermography is a nondestructive evaluation method for identifying defects such as fatigue cracks and delaminations, primarily in aerospace components. When a specimen with crack is subjected to mechanical vibrations, friction and/or adhesion hysteresis between vibrating crack faces generates heat. An infrared camera can capture this heat and identify the defect. Vibrothermography has at times, proved to be an effective method for detecting tight and short cracks that other methods may fail to detect. However, long standing issues such as lack of repeatability and incomplete understanding of physics behind crack heat generation have so far failed to instill confidence in ...


Modern Statistical Methods And Uncertainty Quantification For Evaluating Reliability Of Nondestructive Evaluation Systems, Jeremy Scott Knopp Jan 2014

Modern Statistical Methods And Uncertainty Quantification For Evaluating Reliability Of Nondestructive Evaluation Systems, Jeremy Scott Knopp

Browse all Theses and Dissertations

The reliability of Nondestructive Evaluation (NDE) is an important input for risk analysis for sustainment of aging infrastructure. Reliability has typically been quantified via probability of detection (POD) studies. There are three problems with POD modeling methodologies provided in the most recent guidance on the subject:

1) Current models do not estimate the extremes of a POD curve very well because of the assumption that the POD curve approaches zero as flaw size goes to zero, and the POD curve approaches one as the flaw size goes to infinity.

2) The existing 2-parameter logit/probit models can be misused since ...


Damage Detection And Characterization Of Fiber-Reinforced Composites Using Ultrasonics, Ajith Subramanian Jan 2013

Damage Detection And Characterization Of Fiber-Reinforced Composites Using Ultrasonics, Ajith Subramanian

Graduate Theses and Dissertations

Due to the prevalence of fiber-reinforced composites in industrial applications, the need for damage-detection and characterization has increased. Ultrasonic nondestructive testing (NDT) is a powerful and non-invasive method of detecting flaws and defects in composite materials. Air-coupled and immersion UT techniques are used to quantify the effect of matrix microcracking and delamination within the composite laminate. Detection of matrix microcracks in the laminate is of primary concern since microcracking is one of the initial damage modes resulting in local stiffness reduction. The techniques considered include pulse-echo in immersion, angle-beam through-transmission Lamb wave time-of-flight shift and velocity measurements, and angle-beam backscatter ...


Wave Scattering By An Integral Stiffener, Ricky Steven Reusser Jan 2012

Wave Scattering By An Integral Stiffener, Ricky Steven Reusser

Graduate Theses and Dissertations

Integral stiffeners act as a frequency dependent filter for guided plate waves, impeding transmission and limiting the performance of ultrasonic structural health monitoring (SHM) systems. The effect of integral stiffeners on an acoustic leak location system for manned spacecraft is examined. Leaking air is turbulent and generates noise that can be detected by a contact-coupled acoustic array to perform source location and find the air leak. Transmission of guided waves past individual stiffeners is measured across a frequency range of 50 to 400 kHz for both high and low aspect-ratio rectangular stiffeners. Transmission past a low aspect ratio stiffener is ...


Develop Sonic Infrared Imaging Nde For Local Damage Assessment In Civil Structures, Qi He Jan 2010

Develop Sonic Infrared Imaging Nde For Local Damage Assessment In Civil Structures, Qi He

Wayne State University Dissertations

Nondestructive Evaluation (NDE) is an interdisciplinary field of study, which is concerned with the development of analysis techniques and measurement technologies for the quantitative characterization of materials, tissues and structures. Ultrasonic IR Imaging is a novel NDE technique, which combines a short ultrasonic pulse excitation and infrared imaging to detect defects in materials and structures. In this technique, a sound pulse with a frequency in the range of 20-40kHz is infused on a target material for a short duration (usually less than one second). The sonic/ultrasonic sound waves travel into the material and cause rubbing and clapping between the ...


The Mechanics Of Defect Detection In Vibrothermography, Jeremy Blake Renshaw Jan 2009

The Mechanics Of Defect Detection In Vibrothermography, Jeremy Blake Renshaw

Graduate Theses and Dissertations

Vibrothermography is a nondestructive evaluation (NDE) technique that is used to detect surface and sub-surface defects such as cracks, disbonds, and delaminations through observations of vibration-induced frictional heat generation at defects. Frictional heating is observed using an infrared (IR) camera and is used to determine the presence and location of defects. There is a large industrial interest in vibrothermography due to its ability to rapidly detect defects over a large area. Another motivation for using this technology is its ability to find defects, such as tightly-closed cracks, that can be missed using other common NDE techniques. A major hindrance to ...


Distributed Signal Processing Techniques For Wireless Sensor Networks, Erchin Serpedin, Hongbin Li, Aleksandar Dogandžić, Huaiyu Dai, Paul Cotae Jan 2008

Distributed Signal Processing Techniques For Wireless Sensor Networks, Erchin Serpedin, Hongbin Li, Aleksandar Dogandžić, Huaiyu Dai, Paul Cotae

Center for Nondestructive Evaluation Publications

Recent advances in micro-electromechanical systems (MEMSs) technology have enabled the design of low-power lowcost smart sensors equipped with multiple onboard functions such as sensing, computing, and communications. Such intelligent devices networked through wireless links have been referred to as wireless sensor networks and recognized as one of the most important technologies for the 21st century. Wireless sensor networks hold the promise to revolutionize the sensing technology for a broad spectrum of applications, including infrastructure monitoring and surveillance, disaster management, monitoring the health status of humans, plants, animals, and industrial machines, and so forth.


Relating Crack Heating To Vibration For Vibrothermography, Christopher J. Uhl Jan 2008

Relating Crack Heating To Vibration For Vibrothermography, Christopher J. Uhl

Retrospective Theses and Dissertations

Vibrothermography is an inspection technique that detects cracks by observing vibration induced crack heating. Frictional crack heating in a vibrating specimen is directly linked to the resonant vibrational stress on the crack. In simple geometries we can measure the vibrational mode structure and intuit the dynamic vibrational stress field on the crack. This can be used to establish a relationship between crack heating and vibration, which will be critical for vibrothermography to be accepted as a viable inspection technology. We correlate stress to heating by exciting specimens in a well understood and repeatable resonant vibration mode. Through knowledge of the ...


Microwave Nondestructive Evaluation Of Aircraft Radomes, David Bennett Johnson Jan 2008

Microwave Nondestructive Evaluation Of Aircraft Radomes, David Bennett Johnson

Retrospective Theses and Dissertations

As the aviation industry continues to experience increased demand on maintenance turn-around time with decreased budgets, the airlines in particular seek advances in cost and efficiency for inspection technology. Such improvements not only increase aviation safety, but also lead to significant cost savings and avoidances. One particular inspection need is that of aircraft radomes, often found as the nosecone such as that seen in Figure 1.1, housing the plane's weather radar. This structure, fabricated out of low-loss/permittivity composite materials (such as fiberglass), must appear as "electrically transparent" as possible to the radar. Like a window to the ...


Fusion Of Microwave And Eddy Current Data For A Multi-Modal Approach In Evaluating Corrosion Under Paint And In Lap Joints, Kapil Gupta, Mohammad Tayeb Ahmad Ghasr, Sergey Kharkovsky, R. Zoughi, R. Joe Stanley, Ajay Padwal, Matthew O'Keefe, Donald D. Palmer, J. Blackshire, Gary Steffes, N. Wood Mar 2006

Fusion Of Microwave And Eddy Current Data For A Multi-Modal Approach In Evaluating Corrosion Under Paint And In Lap Joints, Kapil Gupta, Mohammad Tayeb Ahmad Ghasr, Sergey Kharkovsky, R. Zoughi, R. Joe Stanley, Ajay Padwal, Matthew O'Keefe, Donald D. Palmer, J. Blackshire, Gary Steffes, N. Wood

Electrical and Computer Engineering Faculty Research & Creative Works

Critical aircraft structures are susceptible to hidden corrosion. Find-it and fix-it approaches are inefficient as it relates to managing the problems associated with corrosion. More comprehensive corrosion information may be obtained using data fusion from several detection and evaluation methods. To this end, microwave, conventional and pulsed eddy current data from a multi-layer corroded panel, representing an aircraft lap joint, are fused and used as inputs to a structural analysis model to obtain a comprehensive snapshot of the corroded environment. This paper presents the data fusion algorithm and the structural analysis model along with a discussion of the results.


Quantification Of Soil Physical Properties By Using X-Ray Computerized Tomography (Ct) And Standard Laboratory (Std) Methods, María A. Sánchez Jan 2003

Quantification Of Soil Physical Properties By Using X-Ray Computerized Tomography (Ct) And Standard Laboratory (Std) Methods, María A. Sánchez

Retrospective Theses and Dissertations

The implementation of x-ray computerized tomography (CT) on agricultural soils has been used in this research to quantify soil physical properties to be compared with standard laboratory (STD) methods. The overall research objective was to more accurately quantify soil physical properties for long-term management systems. Two field studies were conducted at Iowa State University's Northeast Research and Demonstration Farm near Nashua, lA using two different soil management strategies. The first field study was conducted in 1999 using continuous com crop rotation for soil under chisel plow with no-till treatments. The second study was conducted in 2001 on soybean crop ...


Image Segmentation Using Genetic Algorithm And Morphological Operations, Ming Yu Jan 1998

Image Segmentation Using Genetic Algorithm And Morphological Operations, Ming Yu

Retrospective Theses and Dissertations

Image segmentation is a fundamental component of picture processing and image analysis. Segmentation of an image entails the division or separation of the image into regions of similar attributes. The most basic attribute for segmentation is the image intensity (luminance for a monochromatic image). Several classical methods for image segmentation exist and it is well known that these methods are more or less heuristic and specific to a particular application.

Genetic Algorithms (GA) are stochastic search methods, the functioning of which is inspired by laws of genetics, natural selection and evolution of organisms. Their main attractive characteristic is the ability ...


Photo-Densitometry: Radiograph Digitization And Algorithmic Enhancement Of X-Ray Images, Raghuram Madabushi Jan 1997

Photo-Densitometry: Radiograph Digitization And Algorithmic Enhancement Of X-Ray Images, Raghuram Madabushi

Retrospective Theses and Dissertations

Industrial investigation of material structure and composition is an integral part of the manufacturing design flow. It is possible to evaluate these properties by both destructive and non-destructive means. Non-destructive evaluation of materials is attractive for obvious reasons and x-ray NDE (Non-Destructive Evaluation) is a well established discipline. X-ray images of materials (represented and stored in the form of radiographs) are capable of providing valuable information regarding the presence of material defects such as, voids, cracks and inclusions. A common medium used to store an x-ray image is the film or radiograph. This is an analog representation of the x-ray ...


Automation Of Real-Time X-Ray Scans, Madhusudhan R. Midhe Jan 1996

Automation Of Real-Time X-Ray Scans, Madhusudhan R. Midhe

Retrospective Theses and Dissertations

The present day needs of the commercial market have forced the industry to manufacture materials which are stronger, weigh less and cost less. In other words, it is of prime concern to characterize the material properties. The characterization of a material can be done either at the time of fabrication or while the material is being used. A material can be tested in two ways, destructively or non-destructively. In destructive means of testing materials, a sample is selected randomly from a batch and is inspected thoroughly and the results are extrapolated in a manner so that they represent the whole ...


Detectability Model For The Evaluation Of Lossy Compression Methods On Radiographic Images, Vivek Ramaswami Jan 1996

Detectability Model For The Evaluation Of Lossy Compression Methods On Radiographic Images, Vivek Ramaswami

Retrospective Theses and Dissertations

The purpose of image data compression is to represent data efficiently without loss of information. This involves identification and removal of unnecessary information. Uncompressed image data is typically represented in such a way so that it is highly redundant. Need for data reduction arises due to limitation on storage space or transmission time. Although the storage capacities of magnetic media increases, the demand for data compression has been growing steadily. The Nuclear Regulatory Commission requires that the radiographs be stored for 100 years. The film radiograph degrades due to aging. To avoid this generally the radiograph is digitized between 35 ...


Development Of A Pulsed Eddy Current Instrument For Corrosion Detection, Sunil K. Shaligram Jan 1996

Development Of A Pulsed Eddy Current Instrument For Corrosion Detection, Sunil K. Shaligram

Retrospective Theses and Dissertations

The pulsed eddy current technique has been under development at Iowa State University since 199:3 under the supervision of Mr. John Moulder. It has shown much promise for detecting corrosion and cracks in multi-layered aircraft structures, and has elicited strong interest from the aviation community. The Pulsed Eddy Current Group at the Center for Nondestructive Evaluation, ISU, has built an instrument which utilizes the theory behind pulsed eddy currents and transforms it into a practical field instrument.


Radiographic Imaging Of Microstructural Defects In Ceramic Tapes, Clay W. Maranville Jan 1996

Radiographic Imaging Of Microstructural Defects In Ceramic Tapes, Clay W. Maranville

Retrospective Theses and Dissertations

A prototype method was developed utilizing recent advances in x-ray microfocus radiography and image processing to study the effects of ceramic tape casting variables on microstructure development. The system was designed to incorporate several advantages over traditional, ceramic characterization routes: (i) the system functions as an area detector (rather than a conventional point- or line-detector) providing rapid, statistical information on inhomogeneities in tape microstructures; (ii) it is capable of detecting small pores and surface pits on the order of 10 microns in size; (iii) it can also detect tape thickness variations on the order of 10 microns; (iv) it is ...


Tissue Characterization Using A-Mode Ultrasound For Beef Quality Grading, 1992-1995, Alpesh B. Patel Jan 1995

Tissue Characterization Using A-Mode Ultrasound For Beef Quality Grading, 1992-1995, Alpesh B. Patel

Retrospective Theses and Dissertations

Many of the modern medical diagnostic and material characterization technologies are a direct result of clever use of ultrasound. Ultrasound, for example, is used very widely as a tool for characterizing tissue in medical applications. It is also used extensively in other applications such as nondestructive testing and fluid flow measurements. The objective of the research described in this thesis is to develop a computer based ultrasound system for characterizing beef tissue for quality grading. Extensive research has been performed with regard to tissue characterization in medical applications. Similar work has also been carried out using ultrasound for structural analysis ...


Elastic Property Estimation In Thin Graphite Epoxy Composite Plates Using Ultrasonic Nondestructive Evaluation, Douglas L. Van Otterloo Jan 1995

Elastic Property Estimation In Thin Graphite Epoxy Composite Plates Using Ultrasonic Nondestructive Evaluation, Douglas L. Van Otterloo

Retrospective Theses and Dissertations

The past few decades have seen a steady increase in the use of composite materials. First, as non-load bearing structures such as nose cones and control surfaces and more recently as primary structure. Composite materials can have strength to weight ratios higher than any homogeneous material which makes them very attractive structural materials for the aerospace industry. Unfortunately, in previous years, the failure and performance of composites was not well understood. This eliminated them from use as primary structure. Since the early years of their development, composites have become much more reliable and offer higher strength to weight ratios than ...


Software Modeling For Flaw Characterization Of Metals Through Eddy-Currents, Radhika Satveli Jan 1995

Software Modeling For Flaw Characterization Of Metals Through Eddy-Currents, Radhika Satveli

Retrospective Theses and Dissertations

Nondestructive evaluation (NDE) consists of methods and techniques for the periodic testing of materials and structures that do not require machine disassembly. Electromagnetic NDE makes use of electromagnetic induction, fields, or varying currents for probing and measuring the test samples and thus achieving NDE goals. The electromagnetic NDE cycle is as depicted in Figure 1.1. Eddy current NDE falls in the category of electromagnetic NDE.


The Current Status Of Two Year Plus Three Year Articulation Of Nondestructive Testing Programs, Arnold A. Prosch Jan 1994

The Current Status Of Two Year Plus Three Year Articulation Of Nondestructive Testing Programs, Arnold A. Prosch

Retrospective Theses and Dissertations

Nondestructive testing (NDT) is a means of examining a material, product, or component (either internally or externally) without altering the item in any way that would impair its usefulness. Nondestructive testing can be used on raw materials, materials or components in process, or on a finished product. In addition, in-service NDT inspections may be conducted during the lifetime of the component. Originally used mainly for industrial products, NDT increased greatly with the advent ofWorld War II. The value ofNDT is seen in one's ability to test a product incurring no alteration whatsoever. Whereas other methods of detecting flaws may ...


Application Of The X-Ray Measurement Model To Image Processing Of X-Ray Radiographs, Elizabeth M. Siwek Jan 1994

Application Of The X-Ray Measurement Model To Image Processing Of X-Ray Radiographs, Elizabeth M. Siwek

Retrospective Theses and Dissertations

Information can be conveyed in many forms, yet it is perhaps easiest interpreted when in a visual form. The human mind has the ability to look at a scene containing complex patterns and extract particular features by considering the content of the entire image and focusing on the items of interest. The processing power, speed to decipher images, and complexity of the human brain has yet to be matched by any artificial means. Although the brain is a excellent processor and interpreter, a human can tire and become less accurate with time, potentially causing costly errors. Since consistency is especially ...


Measurement Of Elastic Moduli Of Porous Sic/Sic Ceramic Matrix Composites Using Ultrasonics, Vikram Saini Jan 1994

Measurement Of Elastic Moduli Of Porous Sic/Sic Ceramic Matrix Composites Using Ultrasonics, Vikram Saini

Retrospective Theses and Dissertations

Forced Chemical Vapor Infiltration (FCVI) method was used in fabricating the Nicalon™/Silicon Carbide composites. Both through-thickness and In-plane (fiber fabric plane) moduli were determined using ultrasonic techniques. The through-thickness moduli were found to be much less than the inplane moduli. Both in-plane and through-thickness moduli were significantly decreased with an increased porosity. The experimental results for the moduli were found to be in good agreement with a theoretical model.


Low Frequency Ultrasonic Nondestructive Inspection Of Aluminum/Adhesive Fuselage Lap Splice, Thadd C. Patton Jan 1993

Low Frequency Ultrasonic Nondestructive Inspection Of Aluminum/Adhesive Fuselage Lap Splice, Thadd C. Patton

Retrospective Theses and Dissertations

The Federal Aviation Administration's (FAA) Center for Aviation Systems Reliability (CASR), located at Iowa State University (ISU), was established in 1990 in response to the Aviation Safety Act (Public Law 100-591) of 1988. The Aviation Safety Act, created primarily as the result of an in-flight mishap involving an Aloha Airlines' Boeing 737, mandated that the FAA develop research technologies to aid the aviation industry to (1) better predict the effects of design, maintenance, testing, wear, and fatigue life of an aircraft; (2) develop methods for improving aircraft maintenance technology and practices; and (3) expand general long-range research activities applicable ...