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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.


Recent Advances In Model-Assisted Probability Of Detection, R. Bruce Thompson, Lisa H. Brasche, D. Forsyth, E. Lindgren, P. Swindell, W. Winfree Jun 2009

Recent Advances In Model-Assisted Probability Of Detection, R. Bruce Thompson, Lisa H. Brasche, D. Forsyth, E. Lindgren, P. Swindell, W. Winfree

Center for Nondestructive Evaluation Conference Papers, Posters and Presentations

The increased role played by probability of detection (POD) in structural integrity programs, combined with the significant time and cost associated with the purely empirical determination of POD, provides motivation for alternate means to estimate this important metric of NDE techniques. One approach to make the process of POD estimation more efficient is to complement limited empirical experiments with information from physics-based models of the inspection process or controlled laboratory experiments. The Model-Assisted Probability of Detection (MAPOD) Working Group was formed by the Air Force Research Laboratory, the FAA Technical Center, and NASA to explore these possibilities. Since the 2004 ...


Multiscale Modeling Of Impact On Heterogeneous Viscoelastic Solids With Evolving Microcracks, Flavio V. Souza Apr 2009

Multiscale Modeling Of Impact On Heterogeneous Viscoelastic Solids With Evolving Microcracks, Flavio V. Souza

Engineering Mechanics Dissertations & Theses

Multiscale computational techniques play a major role in solving problems related to viscoelastic composite materials due to the complexities inherent to these materials. In the present work, a numerical procedure for multiscale modeling of impact on heterogeneous viscoelastic solids containing evolving microcracks is proposed in which the (global scale) homogenized viscoelastic incremental constitutive equations have the same form as the local scale viscoelastic incremental constitutive equations, but the homogenized tangent constitutive tensor and the homogenized incremental history dependent stress tensor depend on the amount of damage accumulated at the local scale. Furthermore, the developed technique allows the computation of the ...


Engineering Studies For Fluorescent Penetrant Inspection With A Focus On Developer Application Methods, Lisa Brasche, Rick Lopez, David J. Eisenmann, Keith Griffiths Feb 2009

Engineering Studies For Fluorescent Penetrant Inspection With A Focus On Developer Application Methods, Lisa Brasche, Rick Lopez, David J. Eisenmann, Keith Griffiths

Center for Nondestructive Evaluation Publications

Fluorescent penetrant inspection (FPI) is the most widely used global inspection method, playing a particularly important role in aviation. Given the contribution that reliable implementation of the FPI process can make to flight safety, the US Federal Aviation Administration (FAA) has funded a programme to assess the FPI parameters and their role in effective detection of typical flaws. Iowa State University’s Center for NDE (CNDE) has led a team that includes many industry partners from the aviation industry during this six-year programme. The industry partners have provided guidance and prioritisation input, and in many cases access to internal data ...


Understanding Practical Limits To Heavy Truck Drag Reduction, Drew Landman, Richard Wood, Whitney Seay, John Bledsoe Jan 2009

Understanding Practical Limits To Heavy Truck Drag Reduction, Drew Landman, Richard Wood, Whitney Seay, John Bledsoe

Mechanical & Aerospace Engineering Faculty Publications

A heavy truck wind tunnel test program is currently underway at the Langley Full Scale Tunnel (LFST). Seven passive drag reducing device configurations have been evaluated on a heavy truck model with the objective of understanding the practical limits to drag reduction achievable on a modern tractor trailer through add-on devices. The configurations tested include side skirts of varying length, a full gap seal, and tapered rear panels. All configurations were evaluated over a nominal 15 degree yaw sweep to establish wind averaged drag coefficients over a broad speed range using SAE J1252. The tests were conducted by first quantifying ...


Volume Viscosity In Fluids With Multiple Dissipative Processes, Allan J. Zuckerwar, Robert L. Ash Jan 2009

Volume Viscosity In Fluids With Multiple Dissipative Processes, Allan J. Zuckerwar, Robert L. Ash

Mechanical & Aerospace Engineering Faculty Publications

The variational principle of Hamilton is applied to derive the volume viscosity coefficients of a reacting fluid with multiple dissipative processes. The procedure, as in the case of a single dissipative process, yields two dissipative terms in the Navier-Stokes equation: The first is the traditional volume viscosity term, proportional to the dilatational component of the velocity; the second term is proportional to the material time derivative of the pressure gradient. Each dissipative process is assumed to be independent of the others. In a fluid comprising a single constituent with multiple relaxation processes, the relaxation times of the multiple processes are ...


High Temperature Oxidation Behavior Of Nb-20mo-15si-5b-20cr Alloy, Julieta Angelica Ventura Jan 2009

High Temperature Oxidation Behavior Of Nb-20mo-15si-5b-20cr Alloy, Julieta Angelica Ventura

Open Access Theses & Dissertations

Materials for high temperature applications, such as jet engines, gas turbines and turbine blades, require a balanced combination of physical and chemical properties to withstand the aggressive environments in which they are utilized. Some of the properties required are high strength, low density, high melting point and good oxidation resistance at elevated temperatures [1-3]. For this reason, the microstructure and oxidation behavior of the Nb-20Mo-15Si-5B-20Cr alloy (at.%) has been studied as a potential candidate to replace Nickel-based alloys currently used in the aerospace industry.

Short term oxidation (STO) and long term oxidation (LTO) studies have been performed in air for ...