Download or read book Qualitative and Quantitative Assessments Using Acoustic Emission on Fatigue Crack Growth in Steel Bridges written by Benjamin Bradford Wild and published by . This book was released on 1998 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustic Emission Assessment of Steel Bridge Details Subjected to Fatigue written by Navid Nemati and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Acoustic Emission (AE) fatigue crack monitoring has the potential to provide early fatigue crack detection and assessment required to develop a rational prognostics methodology and can provide insight to assess the integrity of structures such as bridges. Most steel structures develop fatigue cracks at the transverse weld toe of stiffeners, attachments, and cover plates. The cracks develop from a combination of initial conditions (e.g. weld toe geometry, discontinuities, residual stress fields) that are difficult to accurately quantify, thus rendering fracture mechanics models for the prediction of fatigue crack growth exceedingly difficult without experimental verification. Single edge notches provide a very well defined load and fatigue crack size and shape environment for estimation of the stress intensity factor K, which is not found in welded structures. ASTM SE(T) specimens do not appear to provide ideal boundary conditions for proper recording of acoustic wave propagation and crack growth behavior observed in the field, but do provide standard fatigue crack growth rate data. A modified version of the SE(T) specimen has been examined to provide small scale specimens with improved AE characteristics while still maintaining accuracy of fatigue crack growth rate da/dN versus stress intensity factor [delta]K. The configuration of the modified SE(T) specimen maintains the similitude with the orientation of crack propagation in flanges of steel bridge members. Testing of small scale single edge notch tension specimens is considered to assess load ratio (R ratio) and initial crack size effects on fatigue life of specimens. Fatigue tests are conducted at various R ratios to investigate the effect of load ratio on acoustic emission data. Stress Intensity Factor (SIF) models are extended to include expressions for crack tip opening displacement measured experimentally with a clip gauge. Correlation between fatigue crack growth, stress intensity factor and AE data is developed. Analytical and numerical studies of stress intensity factor are developed for single edge notch test specimens consistent with the experimental program. ABAQUS finite element software is utilized for stress analysis of crack tips. Cruciform specimens consisting of a single tension pull plate with transverse fillet welded plates attached at midspan are tested. The transverse plates represent stiffeners and/or short attachments typical of steel bridge details. The specimen provides realistic initial conditions of fatigue crack initiation and growth from high stress concentration regions. Realistic AE waveform characteristics representative of those expected on bridge structures is produced. Accurate stress intensity factor values are more difficult to obtain due to the small, non-uniform crack growth conditions at the weld toe. Additional Finite Element Models for welded geometries capturing stress fields at the weld toe of stiffeners and attachment details is performed to examine crack depth, limited base plate thickness and weld toe angle effects on the relationship between stress intensity factor K and crack size, a. Numerical results are incorporated into an existing analytical stress intensity factor framework to minimize required computational costs. As a result, the validity of Acoustic Emission (AE) as a parameter to assess, monitor and predict the structural health of infrastructure was verified. A methodology to combine AE data and loading data with fracture models was developed to identify and evaluate existing condition (size and shape) and predict future behavior of fatigue cracks on a structure subject to well defined detail types. This will provide the ability to do prognostic using AE and will allow the prediction for the remaining life of the member based on the AE data.
Download or read book Quantitative Acoustic Emission Monitoring of Fatigue Cracks in Fracture Critical Steel Bridges written by Thomas Schumacher (Engineer) and published by . This book was released on 2014 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fatigue Crack Growth Measurement and Data Analysis written by S. J. Hudak and published by ASTM International. This book was released on 1981 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Fatigue Crack Growth Rate of Carburized Gear by Acoustic Emission Technique written by K. Aoki and published by . This book was released on 1991 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Acoustic emission measurements of carburized steel were carried out in room-temperature fatigue tests at the constant load-amplitude condition, in order to evaluate the crack growth behavior. An extremely large number of acoustic emission events were recorded near the maximum load in a flexural fatigue cycle. The increasing behavior of acoustic emission event counts was associated with the distribution of fractured intergranular facets in the fracture surface. Many emissions were also recorded in the spur gear tests. The crack growth rate of the gears can be estimated using the relation between the acoustic emission event counts and the intergranular fracture area on the crack surface. It can be concluded that the acoustic emission technique was powerful and quantitative method to evaluate the fatigue crack behavior of carburized mechanical parts.
Download or read book Fatigue Crack Growth Detection Along A36 Steel Using Acoustic Emission Technique written by Calvin Larod Jones and published by . This book was released on 2008 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: Investigates the monitoring and detecting of crack growth in A36 bridge steel using a new homemade piezoelectric (PZT) sensor. Compares the acoustic emissions (AE) results from attaching conventional sensors and bonded sensors to a steel specimen and putting them under fatigue loading to detect the AE from the crack emission. Completes a finite element simulation to verify the waveform that was produced to the experimental waveform of the bonded sensor.
Download or read book Acoustic Emission Monitoring of Fatigue Cracks in Steel Bridge Structures written by Jay McKeefry and published by . This book was released on 1999 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents results from a laboratory study and field implementation of acoustic emission monitoring or fatigue cracks in cover-plated steel bridge girders. The acoustic monitoring successfully detected growing fatigue cracks in the lab when using both source location and a state of stress criteria. Application of this methodology on 3 field bridges also proved successful by detecting a propagating crack in 2 of the bridges and an extinguished crack in a third bridge.
Download or read book Fatigue Evaluation of Steel Bridges written by Mark Douglas Bowman and published by Transportation Research Board. This book was released on 2012 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: "TRB's National Cooperative Highway Research Program (NCHRP) Report 721: Fatigue Evaluation of Steel Bridges provides proposed revisions to Section 7--Fatigue Evaluation of Steel Bridges of the American Association of State Highway and Transportation Officials Manual for Bridge Evaluation with detailed examples of the application of the proposed revisions."--Publisher's description.
Download or read book Analysis of Acoustic Emission Waveforms from Fatigue Cracks on a Steel Bridge Hanger written by Miguel Fernando G. Sison and published by . This book was released on 1995 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustic Emission Monitoring of Fatigue Cracks on the Fast Steel Bridge written by A. Shakoor Uppal and published by . This book was released on 2005 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Distortion induced Fatigue Cracking in Steel Bridges written by John W. Fisher and published by Transportation Research Board. This book was released on 1990 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustic Emission Characterization of Fatigue Crack Growth in Highway Bridge Components written by Alireza Ghorbanpoor and published by . This book was released on 1985 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fatigue and Fracture in Steel Bridges written by John W. Fisher and published by Wiley-Interscience. This book was released on 1984 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a detailed review and summary of twenty-two case studies of fracture and fatigue in bridge structures. Its two parts cover cracks formed as a result of low fatigue resistant details, and cracks resulting from unanticipated secondary or displacement induced stresses.
Download or read book Acoustic Emission Monitoring of Fatigue Cracks in Steel Bridge Girders written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quantitative Fatigue Crack Measurement by Acoustic Emission written by C. B. Scuby and published by . This book was released on 1991 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study of Fatigue Cracks in Steel Bridge Components Using Acoustic Emissions written by Roy D. Fultineer and published by . This book was released on 1997 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fatigue and Fracture Evaluation for Rating Riveted Bridges written by John W. Fisher and published by Transportation Research Board National Research. This book was released on 1987 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
