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Full-Text Articles in Mechanical Engineering

Ultrasonic Scattering From Ahemispherical Pit Theory And Experimentalmeasurement Precision, Thomas J. Eason, Leonard J. Bond, Mark G. Lozev Jan 2016

Ultrasonic Scattering From Ahemispherical Pit Theory And Experimentalmeasurement Precision, Thomas J. Eason, Leonard J. Bond, Mark G. Lozev

Review of Progress in Quantitative Nondestructive Evaluation

The accuracy and precision of ultrasonic thickness measurement systems are influenced by systematic and environmental factors including the back-wall reflection surface profile. The scattering amplitude from a relatively flat and smooth back-wall surface can be characterized by the acoustic impedance ratio of the two materials at the interface. If the back-wall surface increases in roughness due to internal corrosion, then the arrival time of the incident wave upon the various surface heights will be slightly different, resulting in slight phase changes within the reflected field. In addition, the roughness of the internal surface will result in various impingement anglesrelative to ...


A Parameterized Delamination Model For Use In Complex Damage Characterization Of Composite Laminatesin Ultrasonic Inspections, Heather Reed, Gerald Harvey, Jeff Dobson, Cara Leckey Jan 2016

A Parameterized Delamination Model For Use In Complex Damage Characterization Of Composite Laminatesin Ultrasonic Inspections, Heather Reed, Gerald Harvey, Jeff Dobson, Cara Leckey

Review of Progress in Quantitative Nondestructive Evaluation

Ultrasonic damage detection and characterization is commonly used in nondestructive evaluation (NDE) of aerospace composite components. However, in real materials and structures, the dispersive waves can result in complicated behavior, particularly in the presence of complex damage scenarios and structural components. Accurate three dimensional finite element models (FEMs), using PZFlex, of guided wave interactions with realistic damage scenarios can be used to study quantitative NDE ultrasonic damage detection techniques numerically, to supplement or replace expensive experimental testing. Novel data analysis techniques such as filter reconstruction imaging methods can be used to create practical comparisons between experimental and simulated data. To ...


Compton Imaging Tomography For Nondestructive Evaluation Of Large Multilayer Aircraft Components And Structures, Volodymyr Romanov, Victor Grubsky, Feraidoon Zahiri Jan 2016

Compton Imaging Tomography For Nondestructive Evaluation Of Large Multilayer Aircraft Components And Structures, Volodymyr Romanov, Victor Grubsky, Feraidoon Zahiri

Review of Progress in Quantitative Nondestructive Evaluation

Novel nondestructive evaluation (NDE) systems based on a recently pioneered Compton Imaging Tomography (CIT) technique [1-4 are currently being developed by Physical Optics Corporation (POC). CIT provides high-resolution, three-dimensional (3D), Compton scattered X-ray imaging of the internal structure of evaluated objects, using a set of acquired two-dimensional Compton scattered X-ray images of consecutive cross sections of these objects. Unlike conventional computerized tomography, CIT requires only one-sided access to objects, has no limitation on the dimensions and geometry of such objects, and can be applied to large, multilayer, nonuniform objects. Also, CIT does not require any contact with objects during its ...


Guided Wave Propagation In Porous Unidirectional Cfrp, Nicolas Dobmann, Martin Bach Jan 2016

Guided Wave Propagation In Porous Unidirectional Cfrp, Nicolas Dobmann, Martin Bach

Review of Progress in Quantitative Nondestructive Evaluation

Networks of piezoelectric transducers mounted on aircraft structures for Acousto Ultrasonics (AU) purposes are designed to be applied during the service life of the aircraft. The approach to integrate these sensor networks already during the manufacture of CFRP host structures prompted ideas to achieve an additional benefit by their application for cure monitoring, thus extending their use to the manufacturing chain. This benefit could be extended even further if guided waves generated by AU sensor networks could be used for porosity testing extensively applied for CFRP aircraft structures. In light of this, a study is being conducted to investigate effects ...


Constitutive Damage Variable Measurement In Composites Using Guided Waves, Olivier Mesnil, Massmo Ruzzene Jan 2016

Constitutive Damage Variable Measurement In Composites Using Guided Waves, Olivier Mesnil, Massmo Ruzzene

Review of Progress in Quantitative Nondestructive Evaluation

Cohesive Zone Methods (CZMs) are numerical methods used to numerically simulate damage initiation and growth at the interfaces of composite materials under external loading. These techniques provide estimates of the residual properties of a damaged specimen such as residual strengths, fatigue life or stiffness losses. To run these simulations, it is necessary to measure material properties such as the strengths of the interfaces. To describe the state of the structure at a given time instant during the loading, CZMs define a damage variable D which is a constitutive variable of the structure assessing its current state of health. The literature ...


A Model-Based, Bayesian Solution For Characterization Of Complex Damage Scenarios In Aerospacecomposite Structures, Heather Reed, Gerald Harvey, Jeff Dobson, Cara Leckeyk Jan 2016

A Model-Based, Bayesian Solution For Characterization Of Complex Damage Scenarios In Aerospacecomposite Structures, Heather Reed, Gerald Harvey, Jeff Dobson, Cara Leckeyk

Review of Progress in Quantitative Nondestructive Evaluation

Ultrasonic damage detection and characterization is commonly used in nondestructive evaluation (NDE) of aerospace composite components. In real materials and structures, the dispersive wavesresult in complicated behavior in the presence of complex damage scenarios. Model-based characterization methods utilize accurate three dimensional finite element models(FEMs), using PZFlex, of guided wave interaction with realistic damage scenariosto aid in defect identification & classification. This work builds on the results and methods in [1] and describes an inverse solution for realistic composite damage characterization by comparing the wavenumber- frequency spectra of experimental and simulated UT inspections. The FEM is parameterized with the damage model ...


Study Of Metal Magnetic Memory (Mmm) Technique Using Permanently Installed Magnetic Sensor Arrays, Zhichao Li, Steve Dixon, Peter B. Nagy, Peter Cawley, Rollo Jarvis Jan 2016

Study Of Metal Magnetic Memory (Mmm) Technique Using Permanently Installed Magnetic Sensor Arrays, Zhichao Li, Steve Dixon, Peter B. Nagy, Peter Cawley, Rollo Jarvis

Review of Progress in Quantitative Nondestructive Evaluation

The Metal magnetic memory (MMM) technique is marketed as a non-destructive testing method to evaluate stress concentration for ferromagnetic materials by measuring variations of the self-magnetic leakage field (SMLF) distribution on the specimen surface. This method has been implemented as a periodic screening inspection tool by several companies, and has been reported to be capable of detecting stress concentration in some instances. However, recent literature has suggested that the performance can be unreliable, with many false-calls; however, the reason for the false calls has not been satisfactorily investigated. In this paper, the normal and tangential components of the stress induced ...


Damage Evolution In 3d Woven Composite Materials Using Acoustic Emission, Matthieu Gresil, Mohamed Nasr Saleh, Constantinos Soutis, Mubeen Arshad Jan 2016

Damage Evolution In 3d Woven Composite Materials Using Acoustic Emission, Matthieu Gresil, Mohamed Nasr Saleh, Constantinos Soutis, Mubeen Arshad

Review of Progress in Quantitative Nondestructive Evaluation

Fibre-reinforced composite materials are used extensively in the aerospace industry because of their high specific strength and stiffness, superior corrosion resistance and improved fatigue properties. In addition to the manufacturing costs and production rates, damage tolerance has become a major issue for the composite industry. Three-dimensional (3D) woven composites have superior through-thickness properties compared to two-dimensional (2D) laminate, for example, improved impact damage tolerance, high interlaminar fracture toughness and reduced notch sensitivity. It is a big challenge to relate acoustic emission (AE) signal events to specific damage modes developed in composites under hygro-thermo-mechanical loading [1, 2]. This study provides further ...


Nonlinear Ultrasounic Resonance Spectroscopy Of Intact Carbon Fiber/Epoxy Composites, Sunil Kishore Chakrapani, Daniel J. Barnard, Vinay Dayal Jan 2016

Nonlinear Ultrasounic Resonance Spectroscopy Of Intact Carbon Fiber/Epoxy Composites, Sunil Kishore Chakrapani, Daniel J. Barnard, Vinay Dayal

Review of Progress in Quantitative Nondestructive Evaluation

The present study reports the influence of fiber orientation, laminate sequence and fabric type on the inherent nonlinearity of intact carbon fiber/epoxy composites using nonlinear resonant ultrasonic spectroscopy (NRUS) [1-2]. Fiber orientation of the CFRP samples were changed relative to the length of the sample. Since the fundamental flexural mode is excited, the properties of the composite along the length of the sample would influence the nonlinear response [3]. Two hypothesis were developed using the orientation results and theory of interlaminar stress. Additionally four different laminate sequences were also tested to study the influence of laminate sequence on the ...


Feature Guided Wave Inspection Of A Bond-Line Between A Stiffener And A Composite Plate, X. Yu, Z. Fan, M. Castaings, C. Biateau Jan 2016

Feature Guided Wave Inspection Of A Bond-Line Between A Stiffener And A Composite Plate, X. Yu, Z. Fan, M. Castaings, C. Biateau

Review of Progress in Quantitative Nondestructive Evaluation

Stiffeners are widely used in aircraft structures to increase the structural stiffness. This paper explores the feasibility of using feature guided waves (FGW) for rapid screening of the bond-line between a stiffener and a carbon-fiber-reinforced-polymer (CFRP) composite panel. Such FGW is capable to concentrate the energy along the stiffener and bond-line, with little energy leaking into the plate. Semi-Analytical Finite Element (SAFE) method is applied to understand the modal properties of FGWs that exist in the structure, using both the homogeneous and the heterogeneous model for the composite panel. Promising modes with little dispersion and less little attenuation are identified ...


Model Benchmarking And Reference Signals For Angled-Beam Shear Wave Ultrasonic Nde Inspections, John C. Aldrin, Deborah Hopkins, Mark Warchol, Lyudmila V. Warchol, David S. Forsyth, Charlie Buynak, Eric A. Lindgren Jan 2016

Model Benchmarking And Reference Signals For Angled-Beam Shear Wave Ultrasonic Nde Inspections, John C. Aldrin, Deborah Hopkins, Mark Warchol, Lyudmila V. Warchol, David S. Forsyth, Charlie Buynak, Eric A. Lindgren

Review of Progress in Quantitative Nondestructive Evaluation

NDE modeling and simulation are important tools to support the development and validation of enhanced localization and characterization techniques. Previously, important achievements were made by the USAF to address crack detection in aircraft structures using angled-beam shear wave inspection techniques. However, new work on model benchmarking is needed to move beyond detection and achieve reliable crack characterization. To achieve this goal, simulated studies are needed to verify that models can accurately represent all of the key variables with the inspection of multilayer structures with fastener sites and varying crack conditions. Often with model benchmark studies, the accuracy of the model ...


E-Book Of Abstracts, 41st Annual Review Of Progress In Quantitative Nondestructive Evaluation Conference, Center For Nondestructive Evaluation, Iowa State University Jul 2014

E-Book Of Abstracts, 41st Annual Review Of Progress In Quantitative Nondestructive Evaluation Conference, Center For Nondestructive Evaluation, Iowa State University

Review of Progress in Quantitative Nondestructive Evaluation

Abstracts of papers presented at the 2014 Review of Progress in Quantitative Nondestructive Evaluation (QNDE) conference held in Boise, Idaho from July 20–25, 2014.


Abstracts, Review Of Progress In Quantitative Nondestructive Evaluation (Baltimore, Md, July 21–26, 2013), Center For Nondestructive Evaluation, Iowa State University Jul 2013

Abstracts, Review Of Progress In Quantitative Nondestructive Evaluation (Baltimore, Md, July 21–26, 2013), Center For Nondestructive Evaluation, Iowa State University

Review of Progress in Quantitative Nondestructive Evaluation

Abstracts of papers presented at the 2013 Review of Progress in Quantitative Nondestructive Evaluation (QNDE) conference held in Baltimore, Maryland from July 21–26, 2013.


Abstracts, Review Of Progress In Quantitative Nondestructive Evaluation (Denver, Co, July 15–20, 2012), Center For Nondestructive Evaluation, Iowa State University Jul 2012

Abstracts, Review Of Progress In Quantitative Nondestructive Evaluation (Denver, Co, July 15–20, 2012), Center For Nondestructive Evaluation, Iowa State University

Review of Progress in Quantitative Nondestructive Evaluation

Abstracts of papers presented at the 2012 Review of Progress in Quantitative Nondestructive Evaluation (QNDE) conference held in Denver, Colorado from July 15–20, 2012.


Abstracts, Review Of Progress In Quantitative Nondestructive Evaluation (Burlington, Vermont, July 17-22, 2011), Center For Nondestructive Evaluation, Iowa State University Jul 2011

Abstracts, Review Of Progress In Quantitative Nondestructive Evaluation (Burlington, Vermont, July 17-22, 2011), Center For Nondestructive Evaluation, Iowa State University

Review of Progress in Quantitative Nondestructive Evaluation

Abstracts of papers presented at the 2011 Review of Progress in Quantitative Nondestructive Evaluation (QNDE) conference held in Burlington, Vermont from July 17–22, 2011.


Abstracts, Review Of Progress In Quantitative Nondestructive Evaluation (San Diego, Ca, July 18-23, 2010), Center For Nondestructive Evaluation, Iowa State University Jul 2010

Abstracts, Review Of Progress In Quantitative Nondestructive Evaluation (San Diego, Ca, July 18-23, 2010), Center For Nondestructive Evaluation, Iowa State University

Review of Progress in Quantitative Nondestructive Evaluation

Abstracts of papers presented at the 2010 Review of Progress in Quantitative Nondestructive Evaluation (QNDE) conference held in San Diego, California from July 18–23, 2010.


Abstracts, Review Of Progress In Quantitative Nondestructive Evaluation (Kingston, Ri, July 26–31, 2009), Center For Nondestructive Evaluation, Iowa State University Jul 2009

Abstracts, Review Of Progress In Quantitative Nondestructive Evaluation (Kingston, Ri, July 26–31, 2009), Center For Nondestructive Evaluation, Iowa State University

Review of Progress in Quantitative Nondestructive Evaluation

Abstracts of papers presented at the 2009 Review of Progress in Quantitative Nondestructive Evaluation (QNDE) conference held in Kingston, Rhode Island from July 26–31, 2009.


Abstracts, Review Of Progress In Quantitative Nondestructive Evaluation (Chicago, Il, July 20–25, 2008), Center For Nondestructive Evaluation, Iowa State University Jul 2008

Abstracts, Review Of Progress In Quantitative Nondestructive Evaluation (Chicago, Il, July 20–25, 2008), Center For Nondestructive Evaluation, Iowa State University

Review of Progress in Quantitative Nondestructive Evaluation

Abstracts of papers presented at the 2008 Review of Progress in Quantitative Nondestructive Evaluation (QNDE) conference held in Chicago, Illinois from July 20–25, 2008.


Abstracts, Review Of Progress In Quantitative Nondestructive Evaluation (Golden, Co, July 22–27, 2007), Center For Nondestructive Evaluation, Iowa State University Jul 2007

Abstracts, Review Of Progress In Quantitative Nondestructive Evaluation (Golden, Co, July 22–27, 2007), Center For Nondestructive Evaluation, Iowa State University

Review of Progress in Quantitative Nondestructive Evaluation

Abstracts of papers presented at the 2007 Review of Progress in Quantitative Nondestructive Evaluation (QNDE) conference, held in Golden, Colorado from July 22–27, 2007.


Abstracts, Review Of Progress In Quantitative Nondestructive Evaluation (Portland, Or, July 20–August 4, 2006), Center For Nondestructive Evaluation, Iowa State University Jun 2006

Abstracts, Review Of Progress In Quantitative Nondestructive Evaluation (Portland, Or, July 20–August 4, 2006), Center For Nondestructive Evaluation, Iowa State University

Review of Progress in Quantitative Nondestructive Evaluation

Abstracts of papers presented at the 2006 Review of Progress in Quantitative Nondestructive Evaluation (QNDE) conference held in Portland, Oregon from July 30–August 4, 2006.


Abstracts, Review Of Progress In Quantitative Nondestructive Evaluation (Brunswick, Me, July 31–August 5, 2005), Center For Nondestructive Evaluation, Iowa State University Jul 2005

Abstracts, Review Of Progress In Quantitative Nondestructive Evaluation (Brunswick, Me, July 31–August 5, 2005), Center For Nondestructive Evaluation, Iowa State University

Review of Progress in Quantitative Nondestructive Evaluation

Abstracts of papers presented at the 2005 Review of Progress in Quantitative Nondestructive Evaluation (QNDE) conference held in Brunswick, ME from July 31–August 5, 2005.


Abstracts, Review Of Progress In Quantitative Nondestructive Evaluation (Golden, Co, July 25–30, 2004), Center For Nondestructive Evaluation, Iowa State University Jul 2004

Abstracts, Review Of Progress In Quantitative Nondestructive Evaluation (Golden, Co, July 25–30, 2004), Center For Nondestructive Evaluation, Iowa State University

Review of Progress in Quantitative Nondestructive Evaluation

Abstracts of papers presented at the 2004 Review of Progress in Quantitative Nondestructive Evaluation (QNDE) conference, held in Golden, Colorado from July 25–30, 2004.


Abstracts, Review Of Progress In Quantitative Nondestructive Evaluation (Bellingham, Wa, July 14–19, 2002), Review Of Progress In Quantitative Nondestructive Evaluation Jul 2002

Abstracts, Review Of Progress In Quantitative Nondestructive Evaluation (Bellingham, Wa, July 14–19, 2002), Review Of Progress In Quantitative Nondestructive Evaluation

Review of Progress in Quantitative Nondestructive Evaluation

Abstracts of papers presented at the 2002 Review of Progress in Quantitative Nondestructive Evaluation (QNDE) conference held in Bellingham, Washington from July 14–19, 2002.


Abstracts, Review Of Progress In Quantitative Nondestructive Evaluation (Brunswick, Me, July 29–August 3, 2001), Review Of Progress In Quantitative Nondestructive Evaluation Jul 2001

Abstracts, Review Of Progress In Quantitative Nondestructive Evaluation (Brunswick, Me, July 29–August 3, 2001), Review Of Progress In Quantitative Nondestructive Evaluation

Review of Progress in Quantitative Nondestructive Evaluation

Abstracts of papers presented at the 2001 Review of Progress in Quantitative Nondestructive Evaluation (QNDE) conference, held in Brunswick, Maine from July 29–August 3, 2001.


Ultrasonic Scattering From A Crack Which Emanates From A Rivet Hole, David Budreck Jan 1993

Ultrasonic Scattering From A Crack Which Emanates From A Rivet Hole, David Budreck

Review of Progress in Quantitative Nondestructive Evaluation

In this article we present the exact solution, to first order of the interacting field, of the following canonical problem. We consider the scattering system consisting of an isotropic elastic medium containing an infinite cylindrical void (= hole), from which emanates a half-penny-shaped crack. The crack lies in a plane containing the axis of the cylindrical void, also the crack intersects the void at its own axis of symmetry. In the paragraph below we define what is meant by obtaining the solution ‘to first order’.


Scattering By An Infinite Array Of Randomly Spaced Coplanar Cracks, Yozo Mikata Jan 1993

Scattering By An Infinite Array Of Randomly Spaced Coplanar Cracks, Yozo Mikata

Review of Progress in Quantitative Nondestructive Evaluation

In this paper, the investigation is carried out for the scattering of an anti-plane shear (SH) wave by an infinite array of randomly spaced coplanar cracks. This study was motivated by the desire to better understand the detection and characterization of a flaw plane, i.e., a plane of microcracks, in a more realistic situation. The first thing we can do to model a flaw plane is to model it as a periodic array of cracks [1–5]. In reality, however, an array of cracks is never periodic but rather random. Thus in a previous paper [6], we have treated ...


Ultrasonic Oblique Incidence In Anisotropic Media, Xiang Zhao, Davis M. Egle Jan 1993

Ultrasonic Oblique Incidence In Anisotropic Media, Xiang Zhao, Davis M. Egle

Review of Progress in Quantitative Nondestructive Evaluation

Determining the elastic moduli of anisotropic materials via non-destructive testing techniques is one of the most difficult subjects of acoustoelasticity theory today. The major difficulty comes from the fact that the elastic waves propagating in anisotropic media have different phase and group velocities in both magnitude and direction, which was considered to greatly complicate the analysis of the problem. Therefore, previous work in this area has been restricted to either measurements conducted only in symmetry planes, as mentioned in [1,2], or the slight anisotropy case in which the ultrasonic measurement was approximately related to the phase velocity, such as ...


Guided Waves In Piezoelectric Plates, Hual-Te Chien, Adnan H. Nayfeh, Che-Hua Yang, Dale E. Chimenti Jan 1993

Guided Waves In Piezoelectric Plates, Hual-Te Chien, Adnan H. Nayfeh, Che-Hua Yang, Dale E. Chimenti

Review of Progress in Quantitative Nondestructive Evaluation

In recent paper [1] Nayfeh and Chimenti presented the analysis of the propagation of free waves in a general anisotropic plate. Closed form secular equations which isolate the mathematical conditions for symmetric and antisymmetric wave mode propagation in completely separate terms were obtained. By paralleling the procedure of Nayfeh and Chimenti [1], Nayfeh and Chien [2] presented exact solutions for the interaction of elastic waves with fluid-loaded piezoelectric plates. The technique used was shown to formally handle the most general anisotropy (i.e. the triclinic) case. The plate was immersed in liquid and incident waves impinged upon it from the ...


Quantitative Thickness Measurements Of Ice Layers With Remote Ir Detection, D. Heath, William P. Winfree Jan 1993

Quantitative Thickness Measurements Of Ice Layers With Remote Ir Detection, D. Heath, William P. Winfree

Review of Progress in Quantitative Nondestructive Evaluation

Accretion of ice on aerospace structures is a problem affecting take-off safety and aerodynamic performance. The problem is of concern for commercial and military aircraft, on the runway and in flight, when adverse weather conditions allow ice formation to occur. Ice accretion also occurs on aerospace structures when cryogenic fuels are used, if defects in insulators allow cold spots to develop. In particular, ice formation on the space shuttle external tank can result in structural damage during launching if ice of appreciable mass detaches and impacts the orbiter surface.


Structure Characterization With Thermal Wave Imaging, Kurt Bryan Jan 1993

Structure Characterization With Thermal Wave Imaging, Kurt Bryan

Review of Progress in Quantitative Nondestructive Evaluation

Thermal imaging is a technique of recent interest for the nondestructive evaluation of materials. This method attempts to characterize the internal structure of a sample (perhaps to locate flaws-cracks, bubbles, corrosion, etc.) by using its surface temperature response to an external heating. Some recent work on this subject is detailed in [2], [3], [4] and [6].