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 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 Nondestructive Characterization of Materials VIII written by Robert E. Green and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 828 pages. Available in PDF, EPUB and Kindle. Book excerpt: Different physical models for the Snoek-type relaxation in ternary systems (Fe-C-Me) are analyzed from the viewpoint of a distance of interatomic interaction taken into account: For non-saturated from the viewpoint of overlapping of interatomic interaction in b.c.c. alloys the physically sufficient and optimal for the computer simulation is the short-range model, which takes into account the interatomic interaction and the average amount of substitutional atoms in the first coordination shell, only. For high alloyed b.c.c. systems (i.e. with the overlapped interatomic interaction) the carbon atom undergoes an interaction of a few substitutional atoms simultaneously. That leads to the appearance of one broadened Snoek peak. Activation energy of such a peak is summed from the "elastic" and "chemical" interatomic interactions. Experimental results for alloys with b.c.c. solid solution structure and its computer simulations allow to introduce the new criterion for the high alloy state of monophase steels: the high alloyed state corresponds to the situation when substitutional atoms can not be considered any longer as the isolated atoms. From the viewpoint of mechanical spectroscopy this situation corresponds to the appearance of one broadened IF Snoek-type peak instead of two peaks existed for the steels with lower substitutional atom concentration.
Download or read book Structural Materials Technology written by Robert J. Scancella and published by CRC Press. This book was released on 1994-01-01 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the SEM Spring Conference on Experimental Mechanics written by and published by . This book was released on 1986 with total page 1044 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structural Materials Technology written by Paul E. Hartbower and published by CRC Press. This book was released on 2020-08-23 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a collection of papers presented in the NDT Conference held on February 20-23, 1996 at San Diego, California. The conference provided an opportunity to share experience and provide additional input to the Federal Highway Administration.
Download or read book Geodex Structural Information Service written by Geodex International and published by . This book was released on 1986 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 written by Wojciech Sikorski and published by BoD – Books on Demand. This book was released on 2012-03-02 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: Acoustic emission (AE) is one of the most important non-destructive testing (NDT) methods for materials, constructions and machines. Acoustic emission is defined as the transient elastic energy that is spontaneously released when materials undergo deformation, fracture, or both. This interdisciplinary book consists of 17 chapters, which widely discuss the most important applications of AE method as machinery and civil structures condition assessment, fatigue and fracture materials research, detection of material defects and deformations, diagnostics of cutting tools and machine cutting process, monitoring of stress and ageing in materials, research, chemical reactions and phase transitions research, and earthquake prediction.
Download or read book Proceedings of the 1986 SEM Spring Conference on Experimental Mechanics written by Society for Experimental Mechanics (U.S.) and published by . This book was released on 1986 with total page 1040 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structural Engineering in Natural Hazards Mitigation written by Alfredo Hua-Sing Ang and published by . This book was released on 1993 with total page 880 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Dissertation Abstracts International written by and published by . This book was released on 1990 with total page 812 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Nondestructive Evaluation of Highways Utilities and Pipelines IV written by A. E. Aktan and published by SPIE-International Society for Optical Engineering. This book was released on 2000 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nondestructive Evaluation of Highways Utilities and Pipelines written by and published by . This book was released on 2000 with total page 644 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Highway Bridge Inspections written by United States. Congress. House. Committee on Transportation and Infrastructure. Subcommittee on Highways and Transit and published by . This book was released on 2007 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:
