Download or read book On the Axial Crushing and Failure of Aluminum Alloy Tubes written by Jake Andrew Haley and published by . This book was released on 2020 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of aluminum alloys for light-weighting purposes in energy absorbing components of automobiles is hindered by the relatively low ductility and more complicated constitutive behavior of these alloys. This study presents results from series of quasi-static and dynamic axial crushing experiments on extruded Al-6061-T6 circular tubes of varying D/t ratios. A custom drop-weight testing facility was used to perform the dynamic experiments. Crushing led to axisymmetric, mode-2, and mode-3 concertina folding. In the quasi-static experiments, the folding was monitored using time-lapse photography; dynamic crushing was monitored using high-speed photography. The crushing responses and energy absorption capacities are evaluated and failures were recorded. Failure was observed in most of the experiments with the severity depending on the D/t and mode of folding. The experiments are simulated with three-dimensional, nonlinear finite element analysis using the von Mises, the non-quadratic Hosford, and the calibrated anisotropic Yld04-3D models. The Yld04-3D model was found to most accurately reproduce the structural response under both quasi-static and dynamic loadings. This model was used to the monitor the strains induced in two example cases: axisymmetric folding under quasi-static loading, and mode-2 folding under dynamic loading. The analysis predicted maximum strains to develop at locations on the model tube where failure is observed on the specimen in the experiments. It is concluded that the Yld04-3D constitutive model is most suitable for the prediction of the structural response and failure in tube crushing of this aluminum alloy

Download or read book A Study of the Axial Crush Response of Hydroformed Aluminum Alloy Tubes written by Bruce W. Williams and published by . This book was released on 2007 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: There exists considerable motivation to reduce vehicle weight through the adoption of lightweight materials, such as aluminum alloys, while maintaining energy absorption and component integrity under crash conditions. To this end, it is of particular interest to study the crash behaviour of lightweight tubular hydroformed structures to determine how the forming behaviour affects the axial crush response. Thus, the current research has studied the dynamic crush response of both non-hydroformed and hydroformed EN-AW 5018 and AA5754 aluminum alloy tubes using both experimental and numerical methods. Experiments were performed in which hydroforming process parameters were varied in a parametric fashion after which the crash response was measured. Experimental parameters included the tube thickness and the hydroformed corner radii of the tubes. Explicit dynamic finite element simulations of the hydroforming and crash events were carried out with particular attention to the transfer of forming history from the hydroforming simulations to the crash models. The results showed that increases in the strength of the material due to work hardening during hydroforming were beneficial in increasing energy absorption during crash. However, it was shown that thinning in the corners of the tube during hydroforming decreased the energy absorption capabilities during axial crush. Residual stresses resulting from hydroforming had little effect on the energy absorption characteristics during axial crush. The current research has shown that, in addition to capturing the forming history in the crash models, it is also important to account for effects of material non-linearity such as kinematic hardening, anisotropy, and strain-rate effects in the finite element models. A model combining a non-linear kinematic hardening model, the Johnson-Cook rate sensitive model, and the Yld2000-2d anisotropic model was developed and implemented in the finite element simulations. This combined model did not account for the effect of rotational hardening (plastic spin) due to plastic deformation. It is recommended that a combined constitutive model, such as the one described in this research, be utilized for the finite element study of materials that show sensitivity to the Bauschinger effect, strain-rate effects, and anisotropy.

Download or read book Axial Crushing of Aluminum Tubes Experimental Results and Finite Element Modeling written by and published by . This book was released on 2011 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Failure of Laterally Crushed Aluminum Tubes Under Combined Bending and Tension written by Theofilos Giagmouris and published by . This book was released on 2010 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is concerned with the accurate numerical simulation of localized deformation that can develop into necking and failure, induced by combined bending and tension in aluminum alloy shell structures. The study is motivated by the need to establish the onset and evolution of such failures in imploding underwater cylindrical aluminum alloy shell structures. However, failure under combined bending and tension is also of concern in sheet metal forming. Such localized zones of deformation are shown to develop under controlled conditions in specially designed crushing experiments of Al-6061-T6 cylindrical shells. In these experiments shells of finite length and radially constrained ends are crushed laterally by rigid punches. The crushing, which is conducted under displacement control, causes the shell to develop bending and stretching stresses that lead to arcs of localized wall thinning to appear near the radially constrained locations. The local wall thinning develops into depressions with a width of the order of the shell wall thickness. As crushing progresses the depressions deepen, increase their span, become neck-like and develop inclined failures. The crushing was terminated when the first of four such depressions ruptured. After unloading, the shell was sliced along the principal plane of crushing and the most deformed cross sections of the necks were measured using an optical microscope. The crushing experiments were simulated numerically using solid FE models. The material was modeled as a finitely deforming elastic-plastic solid that hardens isotropically using three constitutive models: the first is based on the von Mises yield function, the second on the non-quadratic isotropic Hosford yield function and the third on the anisotropic Yld04-3D yield function. The models were calibrated to the same stress-strain response and to data from a set of radial biaxial experiments conducted on the same alloy tubes. The overall structural response was reproduced well by all models. Apparently such global responses smear out local differences introduced by the shape of the yield function adopted. However, differences between the three constitutive models were observed in the evolution of localization in the depressions. For the von Mises yield function, the localized deformation was significantly milder than in the experiments. The isotropic Hosford yield function produced necks that were closer to the experimental ones, while Yld04-3D produced results that were very close to the measurements. Clearly, and in concert with other applications, the adoption of a non-quadratic yield function is necessary for reproduction of localization and other challenging deformation histories in Al alloys. The addition of anisotropy in such models improves further the predictions. The results also demonstrated that accurate simulation of the evolution of the depressions in the presence of normal contact stresses requires the use of solid elements. Localization is clearly a three-dimensional phenomenon and shell elements reproduce most of the structural response well, but not the depressions and their evolution that eventually cause failure.

Download or read book Energy Absorption of Structures and Materials written by G Lu and published by Elsevier. This book was released on 2003-10-31 with total page 419 pages. Available in PDF, EPUB and Kindle. Book excerpt: This important study focuses on the way in which structures and materials can be best designed to absorb kinetic energy in a controllable and predictable manner. Understanding of energy absorption of structures and materials is important in calculating the damage to structures caused by accidental collision, assessing the residual strength of structures after initial damage and in designing packaging to protect its contents in the event of impact. Whilst a great deal of recent research has taken place into the energy absorption behaviour of structures and materials and significant progress has been made, this knowledge is diffuse and widely scattered. This book offers a synthesis of the most recent developments and forms a detailed and comprehensive view of the area. It is an essential reference for all engineers concerned with materials engineering in relation to the theory of plasticity, structural mechanics and impact dynamics. Important new study of energy absorption of engineering structures and materials Shows how they can be designed to withstand sudden loading in a safe, controllable and predictable way Illuminating case studies back up the theoretical analysis

Download or read book On the Ductile Failure of Thin walled Aluminum Alloy Tubes Under Combined Shear and Tension written by Scott Sumner Haltom and published by . This book was released on 2012 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this thesis is to establish the extent to which materials can be deformed under shear-dominant loadings. Custom Al-6061-T6 tubular specimens are loaded under radial and corner paths of tension and shear to failure. During the experiments, the deformation is monitored in a test section designed to have nearly uniform stress and deformation at large strains while providing minimum constraint to the development of localization that precedes failure. The recorded shear stress-rotation and axial stress-displacement responses exhibit maxima beyond which deformation localizes in a narrow band that is of the order of the 1 mm wall thickness of the test section. For the mainly shear dominated stress paths followed, deformation remained nearly planar allowing for the establishment of both the true stresses and the local deformation strictly from measurements. Results from thirteen radial path experiments as well as from four corner path experiments show the strain at failure to monotonically increase as the mean stress decreases, a result that is in contrast with previously reported results for Al alloys. Also, the measured failure strains are significantly larger than previously reported values. Analysis of corner stress paths investigates the path dependence of localization and failure. Results show little path dependence on the failure strains, but some path dependence on stress maxima and failure stresses. Furthermore, statistical grain-level strain estimates from five of the stress paths revealed a significant variation in strain across the macroscopically observed localization zone. In the neighborhood of the crack tip strains with 25-100% higher levels than the macroscopic values were recorded. This indicates that localization also occurs at a smaller scale than hitherto understood. The difference between the macro strain at failure and the average grain level values increased as the axial/shear stress ratio increased.

Download or read book Advances in Mechanical Engineering written by Vilas R. Kalamkar and published by Springer Nature. This book was released on 2020-06-29 with total page 844 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents select peer-reviewed proceedings of the International Conference on Advances in Mechanical Engineering (ICAME 2020). The contents cover latest research in several areas such as advanced energy sources, automation, mechatronics and robotics, automobiles, biomedical engineering, CAD/CAM, CFD, advanced engineering materials, mechanical design, heat and mass transfer, manufacturing and production processes, tribology and wear, surface engineering, ergonomics and human factors, artificial intelligence, and supply chain management. The book brings together advancements happening in the different domains of mechanical engineering, and hence, this will be useful for students and researchers working in mechanical engineering.

Download or read book Crashworthiness of Composite Thin Walled Structures written by A.G. Mamalis and published by CRC Press. This book was released on 1998-08-18 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: FROM THE INTRODUCTION Vehicle crashworthiness has been improving in recent years with attention mainly directed towards reducing the impact of the crash on the passengers. Effort has been spent in experimental research and in establishing safe theoretical design criteria on the mechanics of crumpling, providing to the engineers the ability to design vehicle structures so that the maximum amount of energy will dissipate while the material surrounding the passenger compartment is deformed, thus protecting the people inside. During the last decade the attention given to crashworthiness and crash energy management has been centered on composite structures. The main advantages of fibre reinforced composite materials over more conventional isotropic materials, are the very high specific strengths and specific stiffness which can be achieved. Moreover, with composites, the designer can vary the type of fibre, matrix and fibre orientation to produce composites with proved material properties. Besides the perspective of reduced weight, design flexibility and low fabrication costs, composite materials offer a considerable potential for lightweight energy absorbing structures; these facts attract the attention of the automotive and aircraft industry owing to the increased use of composite materials in various applications, such as frame rails used in the apron construction of a car body and the subfloor of an aircraft, replacing the conventional materials used. Our monograph is intended to provide an introduction to this relatively new topic of structural crashworthiness for professional engineers. It will introduce them to terms and concepts of it and acquaint them with some sources of literature about it. We believe that our survey constitutes a reasonably well-balanced synopsis of the topic.

Download or read book Proceedings of the Multimedia University Engineering Conference MECON 2022 written by Mohamad Yusoff bin Alias and published by Springer Nature. This book was released on 2023-02-10 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is an open access book.The Multimedia University Engineering Conference 2022 (MECON 2022) aims to bring together related research scholars, educators, practitioners, policy makers, enthusiasts, fellow students, and industries to share and exchange their research experiences and results on all aspects of engineering technologies from various perspectives, disciplines, and fields. It also offers an interdisciplinary platform for all stakeholders to present and discuss the most latest trends, innovations, and concerns as well as practical challenges encountered, and solutions adopted in the realm of engineering technologies. This conference is being co-organised by the Faculty of Engineering (FOE) and Faculty of Engineering and Technology (FET), Multimedia University. MECON 2022 carries the theme `Sustainable Engineering for a Sustainable Future’.

Download or read book Failure Analysis of Heat Treated Steel Components written by Lauralice de Campos Franceschini Canale and published by ASM International. This book was released on 2008 with total page 651 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings of the International Conference on Advances in Computational Mechanics 2017 written by Hung Nguyen-Xuan and published by Springer. This book was released on 2018-02-20 with total page 1137 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an overview of state-of-the-art methods in computational engineering for modeling and simulation. This proceedings volume includes a selection of refereed papers presented at the International Conference on Advances in Computational Mechanics (ACOME) 2017, which took place on Phu Quoc Island, Vietnam on August 2-4, 2017. The contributions highlight recent advances in and innovative applications of computational mechanics. Subjects covered include: biological systems; damage, fracture and failure; flow problems; multiscale multiphysics problems; composites and hybrid structures; optimization and inverse problems; lightweight structures; computational mechatronics; computational dynamics; numerical methods; and high-performance computing. The book is intended for academics, including graduate students and experienced researchers interested in state-of-the-art computational methods for solving challenging problems in engineering.

Download or read book Behaviour of Thin walled Structures written by J. Rhodes and published by Elsevier Science & Technology. This book was released on 1984 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Handbook of Research on Advancements in the Processing Characterization and Application of Lightweight Materials written by Kumar, Kaushik and published by IGI Global. This book was released on 2021-11-19 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the automotive industry, the need to reduce vehicle weight has given rise to extensive research efforts to develop aluminum and magnesium alloys for structural car body parts. In aerospace, the move toward composite airframe structures urged an increased use of formable titanium alloys. In steel research, there are ongoing efforts to design novel damage-controlled forming processes for a new generation of efficient and reliable lightweight steel components. All these materials, and more, constitute today’s research mission for lightweight structures. They provide a fertile materials science research field aiming to achieve a better understanding of the interplay between industrial processing, microstructure development, and the resulting material properties. The Handbook of Research on Advancements in the Processing, Characterization, and Application of Lightweight Materials provides the recent advancements in the lightweight mat materials processing, manufacturing, and characterization. This book identifies the need for modern tools and techniques for designing lightweight materials and addresses multidisciplinary approaches for applying their use. Covering topics such as numerical optimization, fatigue characterization, and process evaluation, this text is an essential resource for materials engineers, manufacturers, practitioners, engineers, academicians, chief research officers, researchers, students, and vice presidents of research in government, industry, and academia.

Download or read book Ultimate Limit State Analysis and Design of Plated Structures written by Jeom Kee Paik and published by John Wiley & Sons. This book was released on 2018-04-30 with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reviews and describes both the fundamental and practical design procedures for the ultimate limit state design of ductile steel plated structures The new edition of this well-established reference reviews and describes both fundamentals and practical design procedures for steel plated structures. The derivation of the basic mathematical expressions is presented together with a thorough discussion of the assumptions and the validity of the underlying expressions and solution methods. Furthermore, this book is also an easily accessed design tool, which facilitates learning by applying the concepts of the limit states for practice using a set of computer programs, which can be downloaded. Ultimate Limit State Design of Steel Plated Structures provides expert guidance on mechanical model test results as well as nonlinear finite element solutions, sophisticated design methodologies useful for practitioners in industries or research institutions, and selected methods for accurate and efficient analyses of nonlinear behavior of steel plated structures both up to and after the ultimate strength is reached. Covers recent advances and developments in the field Includes new topics on constitutive equations of steels, test database associated with low/elevated temperature, and strain rates Includes a new chapter on a semi-analytical method Supported by a companion website with illustrative example data sheets Provides results for existing mechanical model tests Offers a thorough discussion of assumptions and the validity of underlying expressions and solution methods Designed as both a textbook and a handy reference, Ultimate Limit State Design of Steel Plated Structures, Second Edition is well suited to teachers and university students who are approaching the limit state design technology of steel plated structures for the first time. It also meets the needs of structural designers or researchers who are involved in civil, marine, and mechanical engineering as well as offshore engineering and naval architecture.

Download or read book The Shock and Vibration Digest written by and published by . This book was released on 1989 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1964 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Crushing Strength of Aluminum Tubes written by E. Creutz and published by . This book was released on 1947 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: