Search

Your search keyword '"Abrahams, Ralph"' showing total 23 results
Start Over Author "Abrahams, Ralph"
23 results on '"Abrahams, Ralph"'

3. Tensile Properties and Statistical Analysis of Freestanding YSZ Thin Films with and Without Stress Concentrations

Author

Patibanda, Supriya, Abrahams, Ralph, Jonnalagadda, Krishna N., Cavas-Martínez, Francisco, Series Editor, Chaari, Fakher, Series Editor, di Mare, Francesca, Series Editor, Gherardini, Francesco, Series Editor, Haddar, Mohamed, Series Editor, Ivanov, Vitalii, Series Editor, Kwon, Young W., Series Editor, Trojanowska, Justyna, Series Editor, Jonnalagadda, Krishna, editor, Alankar, Alankar, editor, Balila, Nagamani Jaya, editor, and Bhandakkar, Tanmay, editor

Published
2022
Full Text
View/download PDF

12. THE ROLE OF BOND-LINE DEFECTS IN VARIABLE SLOW BEND TESTS FOR RAIL FLASHBUTT WELDS.

Author

Micheletto, Anthony, Cookson, John, Mutton, Peter, and Abrahams, Ralph

Subjects
BENDING strength, DEFORMATIONS (Mechanics), CRATERING, HEAT treatment, FORGING
Abstract

Flashbutt weld strength is evaluated by slow bend testing of full-size welds. To experimentally investigate the effect of cratering on slow bend test behaviour, trials were performed with artificial craters formed by pre-drilled holes in the ends of rails that were then flash-butt welded together. These artefacts led to only marginally compliant loads and deformation at failure. The fracture surfaces clearly showed anomalies from these artificial crater defects, that became "flatspot" defects or deeper voids and clearly affected the performance of the welds in these slow bend tests. [ABSTRACT FROM AUTHOR]

Published
2023

13. ACOUSTIC EMISSION METHOD FOR NON-DESTRUCTIVE DEFECT DETECTION IN FLASH-BUTT WELDED RAILS.

Author

Fangzhou Zhang, Cookson, John, Mutton, Peter, and Abrahams, Ralph

Subjects
NONDESTRUCTIVE testing, ACOUSTIC emission, STEEL strip, RAILROADS, ELECTRIC noise, TIME-frequency analysis
Abstract

A system is being developed to identify, in near real time, conditions under which flat spot defects are likely to form during Flash-butt Welding (FBW). A key aspect of this system is that it includes measurement of acoustic emission (AE) signals from the welding process. These are intended to identify abnormal events, especially late in the welding cycle. These AE signals are correlated with pressure, displacement and voltage signals acquired at high-frequency sampling rates using an external LabVIEW monitoring system. This paper describes the results of tests performed using this monitoring system to measure the voltages at multiple locations around the weld head and identify issues using the voltage and AE signal during sparking across a rail and a steel strip. The robust realtime high-resolution system has been verified by gathering and comparing the electrical and mechanical noise to the voltage and AE signals in low power experiment tests. A time-frequency analysis technique is under development for assessing flash-butt welding of rails, and the overall system is ready for conducting in-field testing. [ABSTRACT FROM AUTHOR]

Published
2023

17. Residual Stress Measurement Techniques for Metal Joints, Metallic Coatings and Components in the Railway Industry: A Review.

Author

Kendall, Olivia, Paradowska, Anna, Abrahams, Ralph, Reid, Mark, Qiu, Cong, Mutton, Peter, and Yan, Wenyi

Subjects
METAL coating, RESIDUAL stresses, RAILROADS, MATERIAL plasticity, METALS, RAILROAD maintenance & repair
Abstract

Manufacturing and maintenance procedures in the railway industry regularly implement welding and metal deposition operations to produce joints, coatings and repair structures. During these processes, residual stresses arise through the generation of heat affected zones and plastic deformation. This makes accurate measurements of the internal stresses a critical aspect of manufacturing, monitoring, repair and model validation in the develop new metallic coating and joining technologies. Selection of an appropriate residual stress measurement method has many important factors including component size, resolution and the magnitude and location of internal stresses, often resulting in a combination of techniques required to obtain complete assessment of the stress state. This paper offers a review of residual stress measurement techniques for railway components including rail joints and coatings through comparison of destructive and non-destructive approaches, their measurement capabilities, benefits and limitations. A comprehensive discussion of different applications is provided with a summary of facilities available to both research and industry. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

19. Effect of Cladding Direction on Residual Stress Distribution in Laser Cladded Rails

Author

Taposh Roy, Paradowska, Anna, Abrahams, Ralph, Lai, Quan, Law, Michael, Mutton, Peter, Soodi, Mehdi, and Wenyi Yan

Subjects
neutron diffraction, HAZ, residual stress, Laser cladding
Abstract

In this investigation, a laser cladding process with a powder feeding was used to deposit stainless steel 410L (high strength, excellent resistance to abrasion and corrosion, and great laser compatibility) onto railhead (higher strength, heat treated hypereutectoid rail grade manufactured in accordance with the requirements of European standard EN 13674 Part 1 for R400HT grade), to investigate the development and controllability of process-induced residual stress in the cladding, heat-affected zone (HAZ) and substrate and to analyse their correlation with hardness profile during two different laser cladding directions (across and along the track). Residual stresses were analysed by neutron diffraction at OPAL reactor, ANSTO. Neutron diffraction was carried out on the samples in longitudinal (parallel to the rail), transverse (perpendicular to the rail) and normal (through thickness) directions with high spatial resolution through the thickness. Due to the thick rail and thin cladding, 4 mm thick reference samples were prepared from every specimen by Electric Discharge Machining (EDM). Metallography across the laser claded sample revealed four distinct zones: The clad zone, the dilution zone, HAZ and the substrate. Compressive residual stresses were found in the clad zone and tensile residual stress in the dilution zone and HAZ. Laser cladding in longitudinally cladding induced higher tensile stress in the HAZ, whereas transversely cladding rail showed lower tensile behavior., {"references":["F.C.R. Hernández, N.G. Demas, K. Gonzales, and A.A. Polycarpou, Correlation between laboratory ball-on-disk and full-scale rail performance tests. Wear, 2011. 270(7): p. 479-491.","W. Hui, Z. Xu, Y. Zhang, X. Zhao, C. Shao, and Y. Weng, Hydrogen embrittlement behavior of high strength rail steels: A comparison between pearlitic and bainitic microstructures. Materials Science and Engineering: A, 2017. 704: p. 199-206.","K.M. Lee and A.A. Polycarpou, Wear of conventional pearlitic and improved bainitic rail steels. Wear, 2005. 259(1): p. 391-399.","F.C.R. Hernandez, N.G. Demas, D.D. Davis, A.A. Polycarpou, and L. Maal, Mechanical properties and wear performance of premium rail steels. Wear, 2007. 263(1): p. 766-772.","D. Cannon, K.O. EDEL, S. Grassie, and K. Sawley, Rail defects: an overview. Fatigue & Fracture of Engineering Materials & Structures, 2003. 26(10): p. 865-886.","I. Tabernero, A. Lamikiz, S. Martínez, E. Ukar, and J. Figueras, Evaluation of the mechanical properties of Inconel 718 components built by laser cladding. International Journal of Machine Tools and Manufacture, 2011. 51(6): p. 465-470.","P. Webster, K. Low, G. Mills, and G. Webster, Neutron measurement of residual stresses in a used railway rail. MRS Online Proceedings Library Archive, 1989. 166.","G. Webster, P. Webster, M. Bourke, K. Low, G. Mills, H. McGillivray, D. Cannon, and R. Allen, Neutron diffraction determinations of residual stress patterns in railway rails. Residual Stress in Rails, ibid, 1992: p. 143-152.","P. Webster, G. Mills, X. Wang, and W. Kang, Residual stress measurements in rails by neutron diffraction, in Rail Quality and Maintenance for Modern Railway Operation. 1993, Springer. p. 307-314.\n[10]\tV. Luzin, J.E. Gordon, T. Gnaupel-Herold, and H.J. Prask. Neutron residual stress measurements on rail sections for different production conditions. in Proceedings of IMECE. 2004. ASME Anaheim, CA.\n[11]\tZ. Wen, X. Jin, and W. Zhang, Contact-impact stress analysis of rail joint region using the dynamic finite element method. Wear, 2005. 258(7): p. 1301-1309.\n[12]\t12.\tQ. Lai, R. Abrahams, W. Yan, C. Qiu, P. Mutton, A. Paradowska, and M. Soodi, Investigation of a novel functionally graded material for the repair of premium hypereutectoid rails using laser cladding technology. Composites Part B: Engineering, 2017.\n[13]\tJ.C. Ezechidelu and S.O. Enibe, Effect of Heat Treatment on the Microstructure and Mechanical Properties of a Welded AISI 410 Martensitic Stainless Steel.\n[14]\tA. Rajasekhar, G.M. Reddy, T. Mohandas, and V. Murti, Influence of austenitizing temperature on microstructure and mechanical properties of AISI 431 martensitic stainless steel electron beam welds. Materials & Design, 2009. 30(5): p. 1612-1624.\n[15]\tAccess from: http://www.thefabricator.com. Access date: 8th September 2017"]}

Published
2018
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results