Download or read book Finite Element Modelling of Residual Stresses Due to Shot Peening written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Finite Element Modelling of Shot Peening and Strengthening Mechanism Analysis written by Cheng Wang and published by Scientific Research Publishing, Inc. USA. This book was released on 2023-08-25 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: The service performance and life of metal parts are closely related to the surface integrity of materials. Shot peening (SP) is a well-known surface strengthening technique and is widely used for the improvement of the component surface integrity in industrial fields, such as aerospace,vehicle, construction machinery and etc. With the rapid development of science and technology, numerous new SP techniques have been developed from the conventional mechanical shot peening, such as the laser shock peening (LSP), ultrasonic shot peening (USP),surface mechanical attrition treatment (SMAT) and etc. Different from the other mechanical processing techniques, a considerable number of process parameters have an influence on the surface strengthening effects of shot-peened metal parts. Therefore, the selection of the SP process parameters with respect to the different metal parts has always been a challenge. With the rapid development of the computer technology, the numerical simulation has increasingly attracted the more and more attentions both from the academy and the industry. Compared to the experimental investigations, the numerical simulations are not only timesaving and economical, but also can provide an insight into the surface strengthening mechanisms of SP.
Download or read book Finite Element Simulation of Residual Stresses from Welding and High Frequency Hammer Peening written by Gkatzogiannis, Stefanos and published by KIT Scientific Publishing. This book was released on 2022-06-30 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research goal of the present monograph is the establishment of an efficient engineering approach, which will include straightforward but accurate simulation models, in order to estimate the residual stress fields of welded joints introduced during welding and their post-weld treatment with High Frequency Hammer Peening. The present subject lies on the intersection of structural engineering, material science and computational mechanics.
Download or read book Modeling the Residual Stress Distribution and Experimental Characterization of Shot Peening on AZ31B Rolled Sheet written by Amir Yazdanmehr and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The drive to reduce fossil fuel consumption due to its environmental impacts has generated renewed interest in employing magnesium (Mg), the lightest industrial metal, and its alloys in vehicle manufacturing. One of the qualifying metrics for structural application of Mg in transportation vehicles is its high durability. The low fatigue strength of these alloys has been an obstacle to using them in load-bearing components. Thus, methods for improving the fatigue properties of Mg alloys are of interest. Shot peening is a cold-working process employed to improve the fatigue properties of materials. The shot peening process induces compressive residual stress at the material's surface and at a layer in the order of a few hundred micrometers deep, which improves the fatigue life by retarding the crack initiation as well as growth; however, the increased surface roughness has a detrimental effect on fatigue life. These competing effects of peening have created interest in finding the optimum peening intensity that will maximize fatigue life. Modeling reduces the cost of experimentally evaluating optimum peening conditions. However, modeling the shot peening of Mg alloys remains complicated due to the anisotropic and asymmetric properties of wrought Mg alloys, and the complex unloading behavior and rate-sensitivity behavior of these materials. To address these challenges, a comprehensive experimental and numerical-analytical study of shot peening on AZ31B-H24 rolled sheet was conducted and is reported in this thesis. First residual stress distributions through the depth of the material were measured. Among the methods for residual stress measurement, X-ray diffraction (XRD) has attracted researchers' attention because: 1) it is a non-destructive method; 2) it can measure residual stress at the surface, and 3) the spatial resolution can be less than 0.3 mm. However, due to the low x-ray mass attenuation coefficient of Mg alloys, x-ray penetration in the material is significant which needs to be accounted for. The residual stresses in as-received and shot peened AZ31B-H24 rolled sheet samples were measured using the 2D-XRD method. The electro-polishing layer removal method was used to find the residual stress pattern through depth. Due to the high depth of penetration, a correction had to be made to account for the penetration depth. The results showed that the corrected residual stresses in a few tens of micrometers layer from the surface were different from the raw stresses. To better estimate the residual stress distribution in a few micrometers from the surface, the grazing-incidence x-ray diffraction (GIXD) method was applied to evaluate the stresses in the surface layer. This study also showed how small uncertainty in measuring the observed residual stress and in evaluating the depth of the polished area in layer removal leads to high uncertainty in the corrected residual stresses. The XRD results showed the creation of compressive residual stress through the depth as well as a good agreement between the XRD and hole-drilling and GIXD results. Modeling the shot peening process first requires an understanding of how Mg alloys behave at large strain values during loading-unloading. The tension-compression (TC) and compression-tension (CT) in the in-plane directions were obtained using an anti-buckling fixture. By comparing the compression part of the CT curves along the rolling direction (RD) with the ones using a cuboid sample, the negligible effect of using the anti-buckling fixture was shown. A novel fixture was designed to obtain the CT and TC curves in the through-thickness (normal direction: ND) of the rolled sheet, which is only 6.3 mm thick. FEM was employed to evaluate the consistent area for strain measurement using DIC in the designed setup. The CT and TC curves along ND were obtained using the new fixture. The results of the new fixture were verified by comparing the curves obtained by the new fixture in RD with those obtained by using the anti-buckling fixture. Different effects of shot peening on the AZ31B-H24 rolled sheet were characterized in this study by measuring the residual stress and micro-hardness distribution through the depth, followed by measuring surface roughness and texture evolution at the surface of samples shot peened under Almen intensities ranging from 0.05 mmN to 0.6 mmN. To obtain the optimum peening intensity, rotating bending fatigue tests were performed on peened samples at different intensities. It was found that increasing the peening intensity, increases the surface roughness and hardness at the surface layer. In addition, the depth of the maximum compressive stress and the depth of the induced compressive residual stress layer have a direct relation with the peening intensity. The material showed a high sensitivity to shot peening under different intensities, due to the over-peening effects in the peening on Mg alloys. Peening at the optimum intensity increases the fatigue strength moderately, from 130 MPa to 150 MPa. During investigations to find an accurate and a computationally efficient method for capturing the complex behavior of Mg alloys, it was found that stringent assumptions are needed to allow for a closed-form analytical solution when calculating residual stresses induced by shot peening. This limits the application of these models to idealized conditions. On the other hand, and because of the complex behaviors of Mg alloys, such as complex unloading behavior and rate-sensitivity, it is difficult to provide numerical solutions such as finite element that are capable of mimicking actual material's behavior once it is released from an over-strain loading state. Moreover, modeling full coverage shot peening condition is time-consuming and computationally expensive. A single-shot finite element model was combined with an analytical model using actual loading-unloading material behavior to propose a hybrid FEM-analytical model for prediction of the residual stress distribution in shot peening. First, the shot peening process was divided into a loading phase, modeling the impact of a shot and substrate, and an unloading phase, modeling the rebounding of the shot. Finite element was employed to model a single shot impingement on a substrate using the actual loading properties of the substrate. Using the results of the loading phase, an analytical model was proposed to predict stresses due to the unloading phase, using the actual unloading behavior of the material. The proposed hybrid model accounts for the actual behavior of a material, actual elastic-plastic contact analysis, strain rate effect, and friction. The model was then verified by predicting residual stresses induced in a SAE1070 and an Al2024-T351 sheet. Results were compared with the available experimental results and showed close agreements. The application of the proposed hybrid numerical-analytical model was extended to use with an asymmetric and anisotropic material that also has complex unloading behavior, i.e., Mg alloys. First, the loading state of material under peening and the effects of the material's asymmetry and anisotropy were discussed, then the numerical modeling of the loading step was provided. Finally, the actual unloading curves, measured using the designed fixture, of the material were used to estimate the residual stress profiles. The strain rate effect was also considered in the modeling. The results were matched closely with the XRD and hole-drilling experimental measurements.
Download or read book Finite Element Analysis and Design of Experiments for Shot Peening written by Michael Karnas and published by . This book was released on 2013 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shot peening is a cold working manufacturing process designed to induce residual stresses in the surface of the treated material. Theoretical and experimental studies have demonstrated the beneficial effects of shot peening on the fatigue resistance of materials that is a result of the layer of compressive stresses produced in the treated material. Many published studies have used finite element analysis modeling of the peening process to investigate the effects of various peening input parameters on the depth and magnitude of this compressive layer. In the current study, the LS-DYNA code is used to perform 3D dynamic finite element analyses of multiple cast steel high hardness shots impacting a titanium target in an overlapping manner. In contrast to other published analyses, the current work investigates combinations of peening process parameters and their effects on residual stresses. In addition, the current study includes design of experiments to develop regression equations to predict surface stress, maximum residual stress, depth of the maximum residual stress, and the zero-crossing depth using combinations of the peening process input parameters which are shot size, shot velocity, and shot impact angle. Finite element analyses for several different shot peening input parameters are then used in a comparison of results with the regression equations to assess their applicability.
Download or read book A Model for the Prediction of Residual Stresses Resulting from Shot Peening and Its Incorporation Into the ANSYS Finite Element Solver written by Alexander George Broulidakis and published by . This book was released on 2013 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Hybrid Finite Element Analysis of Shot Peen Contour Forming Using Residual Stress Measurements written by James Michael Wagner and published by . This book was released on 2013 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to develop surfaces that have the proper curvature for aerospace structures, it is sometimes necessary to use shot peen forming, also known as contour forming, to create the desired shape in a piece of metal. Since the preferred metal in aerospace continues to be aluminum and its alloys, this study will concentrate on the effects of shot peening on aluminum. Typically, shot intensity is measured using standard Almen strips made from cold rolled SAE 1070 spring steel. Since the effects of the shot on aluminum is the chief concern of this study, aluminum strips of the same size and thickness will be used to determine the intensity of the shot on aluminum parts. These strips will be exposed for different amounts of time to different intensities, measured using the steel Almen strips, and then the intensity (or arc height) will be measured on the aluminum strips. The residual stresses in these strips will then be measured using the hole drill method (ASTM E837). The stresses from the residual stress test will then be used to develop a finite element model that simulates the aluminum strips and the deformation in them. The model will then be calibrated with the empirical data. From there, it will be the goal of this study to be able to predict the deformation of aluminum parts when exposed to certain shot peen intensities. This will enable more efficient contour forming processes with less rework. Furthermore, the trial and error of a manual process can be avoided with the use of robotics. Robotics/Automation can also help in creating more consistent results.
Download or read book Residual Stresses III written by Nihon Zairyō Gakkai and published by . This book was released on 1992 with total page 766 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Finite Element Method written by Păcurar Răzvan and published by BoD – Books on Demand. This book was released on 2018-02-28 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book entitled Finite Element Method: Simulation, Numerical Analysis, and Solution Techniques aims to present results of the applicative research performed using FEM in various engineering fields by researchers affiliated to well-known universities. The book has a profound interdisciplinary character and is mainly addressed to researchers, PhD students, graduate and undergraduate students, teachers, engineers, as well as all other readers interested in the engineering applications of FEM. I am confident that readers will find information and challenging topics of high academic and scientific level, which will encourage them to enhance their knowledge in this engineering domain having a continuous expansion. The applications presented in this book cover a broad spectrum of finite element applications starting from mechanical, electrical, or energy production and finishing with the successful simulation of severe meteorological phenomena.
Download or read book Practical Residual Stress Measurement Methods written by Gary S. Schajer and published by John Wiley & Sons. This book was released on 2013-09-23 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: An introductory and intermediate level handbook written in pragmatic style to explain residual stresses and to provide straightforward guidance about practical measurement methods. Residual stresses play major roles in engineering structures, with highly beneficial effects when designed well, and catastrophic effects when ignored. With ever-increasing concern for product performance and reliability, there is an urgent need for a renewed assessment of traditional and modern measurement techniques. Success critically depends on being able to make the most practical and effective choice of measurement method for a given application. Practical Residual Stress Measurement Methods provides the reader with the information needed to understand key residual stress concepts and to make informed technical decisions about optimal choice of measurement technique. Each chapter, written by invited specialists, follows a focused and pragmatic format, with subsections describing the measurement principle, residual stress evaluation, practical measurement procedures, example applications, references and further reading. The chapter authors represent both international academia and industry. Each of them brings to their writing substantial hands-on experience and expertise in their chosen field. Fully illustrated throughout, the book provides a much-needed practical approach to residual stress measurements. The material presented is essential reading for industrial practitioners, academic researchers and interested students. Key features: • Presents an overview of the principal residual stress measurement methods, both destructive and non-destructive, with coverage of new techniques and modern enhancements of established techniques • Includes stand-alone chapters, each with its own figures, tables and list of references, and written by an invited team of international specialists
Download or read book Finite Element Simulation of Residual Stresses from Welding and High Frequency Hammer Peening written by Stefanos Gkatzogiannis and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Residual Stresses 2016 written by Thomas M. Holden and published by Materials Research Forum LLC. This book was released on 2017-03-15 with total page 638 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the proceedings of the International Conference on Residual Stresses 10 and is devoted to the prediction/modelling, evaluation, control, and application of residual stresses in engineering materials. New developments, on stress-measurement techniques, on modelling and prediction of residual stresses and on progress made in the fundamental understanding of the relation between the state of residual stress and the material properties, are highlighted. The proceedings offer an overview of the current understanding of the role of residual stresses in materials used in wide ranging application areas.
Download or read book Finite Element Dynamic Analysis on Residual Stress Distribution of Titanium Alloy and Titanium Matrix Composite After Shot Peening Treatment written by Lechun Xie and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The residual stress distribution introduced by shot peening (SP) in the deformed surface layer of Ti-6Al-4V and (TiB+TiC)/Ti-6Al-4V were simulated and studied via the three-dimensional (3D) finite element dynamic analysis and the experimental validation. The program of ANSYS/LS-DYNA was utilized, and the 3D homogeneous and inhomogeneous models were set up. The homogeneous model was established for simulating SP process on Ti-6Al-4V. The influence of three important parameters, the shot balls' size, shot velocity and coverage rate on residual stress distribution were investigated. Numerical simulation results showed that these parameters contributed different effects on SP treatment. Using a simplified method, an inhomogeneous model for simulating SP process on (TiB+TiC)/Ti-6Al-4V was set up. The max tensile and compressive residual stress (CRS) was +1155 and −1511 MPa, respectively. Based on this stress distribution, the beneficial effect of reinforcements was indicated during deformation, retarding the damage to the matrix and keeping the adverse tensile stresses in the reinforcements. In order to verify the results of simulation, the residual stress distribution along depth was measured by X-ray diffraction (XRD) method. The residual stress distribution by experiments was agreed with the simulated results, which verified the availability of 3D finite element dynamic analysis.
Download or read book Finite Element Analysis of Residual Stress Field Induced by Laser Shock Peening written by Taeksun Nam and published by . This book was released on 2002 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt: The dynamic behavior of Ti-6A1-4V at high strain rates can be investigated by using the split torsional Hopkinson bar experiment and by a longitudinal shock loading simulation in uniaxial strain to obtain material parameters representing rate dependent plasticity. In case of the double-sided laser peening for a thin part, reversal in loading plays a significant role. The stress waves repeatedly recompose the pre-accumulated plastic strains because of the interaction of the primary and reflected stress waves. In an attempt to better represent the material behavior under repeated reversals and collapses in loading, a sequence of bend-reverse bend tests is performed to identify the material parameters of TI-6A1-4V needed for a nonlinear kinematic hardening model (Chaboche model). For a thick part (a semi-infinite domain), single shot as well as multiple shots (at the same location) cases are simulated and compared with measured data for two different loading magnitudes and three different hardening models. Some of the simulation results agree well with the measured data, depending on the choice of hardening model and the treatment of rate dependent material behavior at high strain rates. Only a single shot (on both sides) case is investigated for a thin part (a finite thickness domain) in terms of residual stress distribution. The disagreement between the computed results and the measured data is more pronounced in this case, needing further investigations on both sides of the fields.
Download or read book Comprehensive Materials Processing written by and published by Newnes. This book was released on 2014-04-07 with total page 5485 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive Materials Processing, Thirteen Volume Set provides students and professionals with a one-stop resource consolidating and enhancing the literature of the materials processing and manufacturing universe. It provides authoritative analysis of all processes, technologies, and techniques for converting industrial materials from a raw state into finished parts or products. Assisting scientists and engineers in the selection, design, and use of materials, whether in the lab or in industry, it matches the adaptive complexity of emergent materials and processing technologies. Extensive traditional article-level academic discussion of core theories and applications is supplemented by applied case studies and advanced multimedia features. Coverage encompasses the general categories of solidification, powder, deposition, and deformation processing, and includes discussion on plant and tool design, analysis and characterization of processing techniques, high-temperatures studies, and the influence of process scale on component characteristics and behavior. Authored and reviewed by world-class academic and industrial specialists in each subject field Practical tools such as integrated case studies, user-defined process schemata, and multimedia modeling and functionality Maximizes research efficiency by collating the most important and established information in one place with integrated applets linking to relevant outside sources
Download or read book Surface Effects and Contact Mechanics X written by J. T. M. De Hosson and published by WIT Press. This book was released on 2011 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contact mechanics and surface effects, as well as their interaction, are important in modern engineering. The life and performance of structural components is affected by surface conditions such as wear, corrosion and, high cycle fatigue. Surface treatments that address contact conditions can reduce costs by extending the life of components. These are the subjects of a biennial conference first held in 1993, the papers from the latest of which are collected in this volume. The book discusses Computer simulation; Surface modification; Surface treatments; Surface problems in contact mechanics; Contact mechanics; Applications and case studies; Indentation and hardness; Thick and thin coatings; Corrosion problems; Nano-characterisation; Test methodology; Multiscale experiments and modelling; and Fracture fatigue and mechanics.
Download or read book Finite Element Analysis for Satellite Structures written by Gasser F. Abdelal and published by Springer Science & Business Media. This book was released on 2012-11-05 with total page 339 pages. Available in PDF, EPUB and Kindle. Book excerpt: Designing satellite structures poses an ongoing challenge as the interaction between analysis, experimental testing, and manufacturing phases is underdeveloped. Finite Element Analysis for Satellite Structures: Applications to Their Design, Manufacture and Testing explains the theoretical and practical knowledge needed to perform design of satellite structures. By layering detailed practical discussions with fully developed examples, Finite Element Analysis for Satellite Structures: Applications to Their Design, Manufacture and Testing provides the missing link between theory and implementation. Computational examples cover all the major aspects of advanced analysis; including modal analysis, harmonic analysis, mechanical and thermal fatigue analysis using finite element method. Test cases are included to support explanations an a range of different manufacturing simulation techniques are described from riveting to shot peening to material cutting. Mechanical design of a satellites structures are covered in three steps: analysis step under design loads, experimental testing to verify design, and manufacturing. Stress engineers, lecturers, researchers and students will find Finite Element Analysis for Satellite Structures: Applications to Their Design, Manufacture and Testing a key guide on with practical instruction on applying manufacturing simulations to improve their design and reduce project cost, how to prepare static and dynamic test specifications, and how to use finite element method to investigate in more details any component that may fail during testing.
