The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
Patrik Šarga - One of the best experts on this subject based on the ideXlab platform.
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Modern Trends in the Field of Measurement of Residual Stresses Using Hole-Drilling Method
American journal of mechanical engineering, 2016Co-Authors: Patrik Šarga, František TrebuňaAbstract:Residual stresses in the constructions have in most cases a negative effect on their overall life. Large numbers of investigations have been carried out to study this phenomenon and its effect on the mechanical characteristics of these constructions or their components. Hole-Drilling Method is one of the most used Methods used for the determination of residual stresses. This Method typically uses strain gauges. This article describes options of using optical Methods instead of strain gauge in the process of evaluation of residual stresses by hole-Drilling Method.
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New Method of Residual Stress Evaluation and its Advantages in Comparison with More Common Hole-Drilling Method
Acta Mechanica Slovaca, 2013Co-Authors: František Menda, František Trebuňa, Patrik ŠargaAbstract:Residual stress evaluation in constructions and mechanical parts is a necessary task in every modern industrial factory. Right evaluated changes in lifetime and loading conditions could save amount of money and increase the human safety. The Department of Applied Mechanics and Mechatronics has a long tradition in developing and practical usage of semi-destructive Methods for determining residual stresses. Especially by using hole-Drilling Method and recently also Ring-Core Method. Main characteristics and comparison of both Methods with emphasis on Ring-Core analysis are discussed in this article.
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Comparison of Ring-Core Method and Hole-Drilling Method Used for Determining Residual Stresses
American journal of mechanical engineering, 2013Co-Authors: Patrik Šarga, František MendaAbstract:Ring-Core Method is derived from a hole-Drilling Method and both are used for determining uniform and non-uniform stress through the thickness of specimen. The reason for creation the Ring-Core Method was to remove some of the shortcomings of hole-Drilling Method. Both Methods are semi-destructive Methods, because they both partially destroy the studied specimens which are subsequently easy to fix and thus they are still useful. The aim of this article is to compare these two Methods and thus help experimentalist to choose the appropriate Method for determining residual stresses. Because Ring-Core Method is less common, we will discuss more about this Method in the article.
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QUANTIFICATION OF RESIDUAL STRESSES IN THE WELD BY THE HOLE-Drilling Method
Metalurgija, 2008Co-Authors: František Trebuňa, Patrik Šarga, František Šimčák, Jozef Bocko, Peter Trebuňa, Miroslav Pástor, J. MihokAbstract:Residual stresses arise in the structures without loading during the technological processes, e.g. casting, rolling, welding, and pressing. In the paper is described the process of quantification of residual stresses by the hole-Drilling Method. For determination of residual stresses were used the procedures in which are supposed constant or linear distributions of stresses along the hole.
František Trebuňa - One of the best experts on this subject based on the ideXlab platform.
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Modern Trends in the Field of Measurement of Residual Stresses Using Hole-Drilling Method
American journal of mechanical engineering, 2016Co-Authors: Patrik Šarga, František TrebuňaAbstract:Residual stresses in the constructions have in most cases a negative effect on their overall life. Large numbers of investigations have been carried out to study this phenomenon and its effect on the mechanical characteristics of these constructions or their components. Hole-Drilling Method is one of the most used Methods used for the determination of residual stresses. This Method typically uses strain gauges. This article describes options of using optical Methods instead of strain gauge in the process of evaluation of residual stresses by hole-Drilling Method.
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New Method of Residual Stress Evaluation and its Advantages in Comparison with More Common Hole-Drilling Method
Acta Mechanica Slovaca, 2013Co-Authors: František Menda, František Trebuňa, Patrik ŠargaAbstract:Residual stress evaluation in constructions and mechanical parts is a necessary task in every modern industrial factory. Right evaluated changes in lifetime and loading conditions could save amount of money and increase the human safety. The Department of Applied Mechanics and Mechatronics has a long tradition in developing and practical usage of semi-destructive Methods for determining residual stresses. Especially by using hole-Drilling Method and recently also Ring-Core Method. Main characteristics and comparison of both Methods with emphasis on Ring-Core analysis are discussed in this article.
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QUANTIFICATION OF RESIDUAL STRESSES IN THE WELD BY THE HOLE-Drilling Method
Metalurgija, 2008Co-Authors: František Trebuňa, Patrik Šarga, František Šimčák, Jozef Bocko, Peter Trebuňa, Miroslav Pástor, J. MihokAbstract:Residual stresses arise in the structures without loading during the technological processes, e.g. casting, rolling, welding, and pressing. In the paper is described the process of quantification of residual stresses by the hole-Drilling Method. For determination of residual stresses were used the procedures in which are supposed constant or linear distributions of stresses along the hole.
Berthold Scholtes - One of the best experts on this subject based on the ideXlab platform.
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Residual Stress Analysis on Thin Metal Sheets Using the Incremental Hole Drilling Method – Fundamentals and Validation
Experimental Techniques, 2019Co-Authors: Arnaud Magnier, Wolfgang Zinn, Thomas Niendorf, Berthold ScholtesAbstract:The aim of the present work is to broaden the scope of application of the hole Drilling Method and to enable reliable residual stress measurements on thin metal sheets. In this context the focus is on characterization of residual stresses on brazed sheet metal constructions. In this specific case coarse grains and low sheet thickness are strong restrictions for standard residual stress measurement Methods. However, in the current work it is shown that it is possible to extend the scope of application of the incremental hole Drilling Method to thin components. For this purpose, calibration coefficient matrices for sheets having thicknesses of 0.7 mm, 1 mm and 1.6 mm have been calculated using finite element analysis. Furthermore, by measuring residual stresses of bent metal sheets, the determined coefficients and measurement procedure feasibility have been validated. Finally, the application of the incremental hole Drilling Method on an austenitic-ferritic brazed sheet metal construction is demonstrated.
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On the reliability of residual stress measurements in polycarbonate samples by the hole Drilling Method
Polymer Testing, 2018Co-Authors: A. Magnier, Berthold Scholtes, Thomas NiendorfAbstract:Abstract The present study introduces a procedure to analyze residual stresses in polymer materials using the hole Drilling Method. This Method is widely applied in metallic materials, however its application in polymer materials is not straightforward. In previous work [1, 2], the experimental set-up was improved to gain reproducible results, however, in-depth analysis of the reliability of measurements was not conducted. In order to gain appropriate information, a known loading stress was introduced in bending samples made of polycarbonate. By measuring the total stresses in the samples and comparing them with theoretical expectations, it is shown that the hole Drilling Method delivers reliable results and has a high potential for residual stress analysis in a variety of polymer materials. Based on this approach, it is shown that the resistance to environmental stress cracking of polycarbonate can be significantly improved by introducing compressive residual stress states.
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Some Aspects of the Application of the Hole Drilling Method on Plastic Materials
Residual Stress Thermomechanics & Infrared Imaging Hybrid Techniques and Inverse Problems Volume 9, 2016Co-Authors: A. Magnier, Andreas Nau, Berthold ScholtesAbstract:Residual stresses are always present in nearly every component as a consequence of the manufacturing process. If the material exhibits a crystalline structure, diffraction Methods are undoubtedly a Method of choice for residual stress analysis. However such a Method is not always applicable on plastics. As they undergo complex manufacturing processes, they also have to be evaluated in terms of introduced residual stresses. Here, mechanical Methods like the incremental hole Drilling Method might be more suitable. However, for a reliable residual stress analysis in plastic materials, the hole Drilling Method usually applied for isotropic metallic materials has to be adapted. A critical point comes from the required strain gauge rosette technique. It involves a stiffening effect due to its assembly and its bonding. Further issues are the stressless introduction of a geometrically defined hole, temperature effects and the viscoelastic behavior of plastic materials. Those critical points were investigated numerically and experimentally on different types of plastic materials in order to improve the hole Drilling Method and to provide an opportunity to estimate more precisely residual stresses.
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Residual Stress Analysis Using the Hole-Drilling Method and Geometry-Specific Calibration Functions
Materials Science Forum, 2011Co-Authors: Enrique Garcia Sobolevski, Andreas Nau, Berthold ScholtesAbstract:Due to the fact that no analytical solution exists to determine residual stresses in components with geometrical deviations from an ideal plate with the well known semi-destructive incremental hole-Drilling Method, calibration functions are required. Currently, such available functions, generated in an experimental or numerical manner are strictly speaking only valid for the reference case of a wide and thick plate and are only applicable if the surrounding field of the geometry at the measurement point is similar to the ideal one. Consequently, accuracy and reliability of assessing residual stresses by means of the incremental hole-Drilling Method can be improved if geometry specific calibration functions adapted to real geometries are used. This work deals with the determination of specific calibration functions by means of numerical simulations according to the MPA II standard (differential Method) for three different components, violating the geometric restrictions of the reference.
Edoardo Bemporad - One of the best experts on this subject based on the ideXlab platform.
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measurement of residual stress in thermal spray coatings by the incremental hole Drilling Method
Surface & Coatings Technology, 2006Co-Authors: Y Y Santana, J G La Barberasosa, M H Staia, J Lesage, E S Puchicabrera, Didier Chicot, Edoardo BemporadAbstract:Abstract The experimental measurement of residual stresses originating within thick coatings deposited by thermal spray processes onto solid substrates plays a fundamental role in the preliminary stages of coating design and process parameters optimization. The main objective of the present investigation was to determine the residual stresses by means of the incremental hole Drilling Method in order to perform the measurement of the stress field through the thickness of two different HVOF Nickel-based coatings. The holes through the coatings were carried out by means of a high velocity Drilling machine (Restan). A finite element calculation procedure was used to identify the calibration coefficients necessary to evaluate the stress field. The Integral Method was used for the analysis of non-uniform through-thickness stresses. The results for both coatings indicate that the nature of the residual stresses is tensile and their values are between 150–300 MPa.
Thomas Niendorf - One of the best experts on this subject based on the ideXlab platform.
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Residual Stress Analysis on Thin Metal Sheets Using the Incremental Hole Drilling Method – Fundamentals and Validation
Experimental Techniques, 2019Co-Authors: Arnaud Magnier, Wolfgang Zinn, Thomas Niendorf, Berthold ScholtesAbstract:The aim of the present work is to broaden the scope of application of the hole Drilling Method and to enable reliable residual stress measurements on thin metal sheets. In this context the focus is on characterization of residual stresses on brazed sheet metal constructions. In this specific case coarse grains and low sheet thickness are strong restrictions for standard residual stress measurement Methods. However, in the current work it is shown that it is possible to extend the scope of application of the incremental hole Drilling Method to thin components. For this purpose, calibration coefficient matrices for sheets having thicknesses of 0.7 mm, 1 mm and 1.6 mm have been calculated using finite element analysis. Furthermore, by measuring residual stresses of bent metal sheets, the determined coefficients and measurement procedure feasibility have been validated. Finally, the application of the incremental hole Drilling Method on an austenitic-ferritic brazed sheet metal construction is demonstrated.
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On the reliability of residual stress measurements in polycarbonate samples by the hole Drilling Method
Polymer Testing, 2018Co-Authors: A. Magnier, Berthold Scholtes, Thomas NiendorfAbstract:Abstract The present study introduces a procedure to analyze residual stresses in polymer materials using the hole Drilling Method. This Method is widely applied in metallic materials, however its application in polymer materials is not straightforward. In previous work [1, 2], the experimental set-up was improved to gain reproducible results, however, in-depth analysis of the reliability of measurements was not conducted. In order to gain appropriate information, a known loading stress was introduced in bending samples made of polycarbonate. By measuring the total stresses in the samples and comparing them with theoretical expectations, it is shown that the hole Drilling Method delivers reliable results and has a high potential for residual stress analysis in a variety of polymer materials. Based on this approach, it is shown that the resistance to environmental stress cracking of polycarbonate can be significantly improved by introducing compressive residual stress states.
