Download or read book Numerical Modelling of Ductile Fracture in Blanking written by Dirk Brokken and published by . This book was released on 1999 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ductile Fracture in Metal Forming written by Kazutake Komori and published by Academic Press. This book was released on 2019-10-11 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ductile Fracture in Metal Forming: Modeling and Simulation examines the current understanding of the mechanics and physics of ductile fracture in metal forming processes while also providing an approach to micromechanical ductile fracture prediction that can be applied to all metal forming processes. Starting with an overview of different ductile fracture scenarios, the book then goes on to explain modeling techniques that predict a range of mechanical phenomena that can lead to ductile fracture. The challenges in creating micromechanical models are addressed alongside methods of applying these models to several common metal forming processes. This book is suitable for researchers working in mechanics of materials, metal forming, mechanical metallurgy, and plasticity. Engineers in R&D industries involved in metal forming such as manufacturing, aerospace, and automation will also find the book very useful. Explains innovative micromechanical modeling techniques for a variety of material behaviors Examines how these models can be applied to metal forming processes in practice, including blanking, arrowed cracks in drawing, and surface cracks in upset forging Provides a thorough examination of both macroscopic and microscopic ductile fracture theory

Download or read book Numerical Modelling of Ductile Fracture written by Odd Perry Søvik and published by . This book was released on 1996 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Modelling of Material Deformation Processes written by Peter Hartley and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt: The principal aim of this text is to encourage the development and application of numerical modelling techniques as an aid to achieving greater efficiency and optimization of metal-forming processes. The contents of this book have therefore been carefully planned to provide both an introduction to the fundamental theory of material deformation simulation, and also a comprehensive survey of the "state-of-the-art" of deformation modelling techniques and their application to specific and industrially relevant processes. To this end, leading international figures in the field of material deformation research have been invited to contribute chapters on subjects on which they are acknowledged experts. The information in this book has been arranged in four parts: Part I deals with plasticity theory, Part II with various numerical modelling techniques, Part III with specific process applications and material phenomena and Part IV with integrated computer systems. The objective of Part I is to establish the underlying theory of material deformation on which the following chapters can build. It begins with a chapter which reviews the basic theories of classical plasticity and describes their analytical representations. The second chapter moves on to look at the theory of deforming materials and shows how these expressions may be used in numerical techniques. The last two chapters of Part I provide a review of isotropic plasticity and anisotropic plasticity.

Download or read book Micromechanics Modelling of Ductile Fracture written by Zengtao Chen and published by Springer Science & Business Media. This book was released on 2013-04-02 with total page 335 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book summarizes research advances in micromechanics modeling of ductile fractures made in the past two decades. The ultimate goal of this book is to reach manufacturing frontline designers and materials engineers by providing a user-oriented, theoretical background of micromechanics modeling. Accordingly, the book is organized in a unique way, first presenting a vigorous damage percolation model developed by the authors over the last ten years. This model overcomes almost all difficulties of the existing models and can be used to completely accommodate ductile damage developments within a single-measure microstructure frame. Related void damage criteria including nucleation, growth and coalescence are then discussed in detail: how they are improved, when and where they are used in the model, and how the model performs in comparison with the existing models. Sample forming simulations are provided to illustrate the model’s performance.

Download or read book Numerical Modeling of Ductile Fracture written by Jun Zhou and published by . This book was released on 2013 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis sought to investigate and develop valid numerical approaches to predict ductile fracture under different stress state and loading conditions. As the first portion of this work, the plastic flow and fracture behaviors of three aluminum alloys (5083-H116, 6082-T6 and 5183 weld metal) under the effects of strain rate and temperature were studied through a series of experiments and finite element analyses. The fracture behavior under the influential factor of stress triaxiality was also studied. The applicability of the Johnson-Cook plasticity and fracture models were investigated with mixed results. For all three materials, the dependency of the failure strain on triaxiality is adequately described. The stress state effect on plasticity and ductile fracture behaviors was further explored for aluminum alloy 5083-H116 through tests on plane strain specimens and torsion specimens, focusing on the third deviatoric stress invariant (lode angle). A stress state dependent plasticity model, J2-J3 model, together with the Xue-Wierzbicki fracture criterion which defined the damage parameter as a function of the stress triaxiality and the Lode angle, was implemented and calibrated with the test data. The calibrated model was utilized to study the residual stress effect on ductile fracture resistance, using compact tension specimens with residual stress fields generated from a local out-of-plane compression approach. Fracture tests with positive and negative residual stresses were conducted on the C(T) specimens. Both experimental and finite element results showed significant effect of residual stress on ductile fracture resistance. In an attempt to predict ductile fracture under shear-dominated conditions, this study combined the damage mechanics concept with the Gurson-Tvergaard-Needleman porous plasticity model that accounts for void nucleation, growth and coalescence. The GTN model was extended by coupling two damage parameters, representing volumetric damage and shear damage respectively, into the yield function and flow potential. The new model was validated through a series of numerical tests in comparison with existing GTN type models, and applied to predict the ductile fracture behaviors of a beta-treated Zircaloy-4. With model parameters calibrated using experimental data, the model was able to predict failure initiation and propagation in various specimens experiencing a wide range of stress states.

Download or read book Numerical model studies on ductile fracture written by Minoru Taya and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Variational Approach to Fracture written by Blaise Bourdin and published by Springer Science & Business Media. This book was released on 2008-04-19 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presenting original results from both theoretical and numerical viewpoints, this text offers a detailed discussion of the variational approach to brittle fracture. This approach views crack growth as the result of a competition between bulk and surface energy, treating crack evolution from its initiation all the way to the failure of a sample. The authors model crack initiation, crack path, and crack extension for arbitrary geometries and loads.

Download or read book Numerical Prediction of Ductile Fracture Due to Moving Load written by Md Abdullah and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This study investigates the effect of moving load on ductile fracture of shipbuilding metals through numerical simulation. Quinton [1,2] and Alsos [3] investigated moving load's effect on metals, in the plastic regime, and found that moving load results in a significant reduction in plastic capacity of metals. This study complements their work by extending the scope of the work up to ductile fracture initiation which was accomplished by implementing state-of-art ductile fracture model in moving loading scenario. A state-of-art ductile fracture model has been implemented in this study by incorporating the knowledge acquired by research in the fracture mechanics arena. A stress state based fracture locus with strain rate and temperature effects has been selected as the ductile fracture criteria accordingly. Finite Element Method with Explicit Time Integration scheme deemed appropriate for numerical simulation and LS-DYNA has been chosen to accomplish this consequently. This study attempts to mitigate two significant limitations of maritime structural assessment techniques associated with ship-ice interaction; undue simplification of load definition and over conservatism on fracture strain selection. Ship-ice interaction is considered as stationary loading scenario while it should be categorised as moving loading condition in accidental overloading situations. In addition, these techniques also regard fracture strain to be constant and independent of stress state, whereas studies show that ductile fracture initiation is highly dependent on the stress state. This study provides a method to incorporate stress-state dependent state-of-art ductile fracture model for numerical investigation of moving load.

Download or read book Development of Numerical Approaches to Predict Ductile and Cleavage Fracture of Structural Materials written by Guihua Zhang and published by . This book was released on 2007 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Numerical simulations mainly using finite element method are playing a more and more important role in prediction of fracture-induced failure for high performance structure. This thesis seeks to develop numerical approaches to predict ductile and cleavage fracture in structural materials. For ductile fracture, the discrete void approach reveals the failure mechanisms explicitly and is used to study the trends of fracture toughness. The porous continuum approach provides an effective means to predict extensive crack propagation. We consider the occurrence of material failure (void coalescence) as when localization of plastic flow takes place in the inter-void ligament and obtain the failure criterion as a function of the stress triaxiality ratio and the Lode angle. The Gologanu-Leblond Devaux (GLD) model, which accounts for the evolution of both void volume and void shape, is used to describe the porous placticity behavior and is implemented into ABAQUS via a user subroutine. Numerical simulations are performed to predict extensive crack growth in ductile solids for a thin aluminum 2024-T3 plate and verified by successful predication of crack extension in various specimens, including the multiple site damage speciments. The effect of stress triaxiality and Lode angle is further analyzed and the Xue-Wierzbicki fracture locus is employed as a criterion for void colescence. Combination of GLD model and X-W fracture locus is then applied to a DH-36 steel with specimens experiencing a wide range of stress triaxiality and Lode angles at failure. The numerical simulation results agree very well with the experimental results. For cleavage fracture, a modified three parameter Weibull stress model is proposed and used to predict the fracture of A508 steel at three different temperatures. By integrating the Weibull stress model over the plastic process zone, the failure probability can be obtained and comparison is made with the experiment result. Issues addressed include calibration of the model parameters, introduction of a threshold parameter, dependencies of the model parameters on temperature, plastic strain effect and crack tip triaxiality effect, etc."--Abstract.

Download or read book Studies on Strain Localization Ductile Fracture and Damage in Structural Metals written by Yazhi Zhu and published by . This book was released on 2017 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the most important limit states in structural metals is ductile fracture, and the prediction of ductile fracture is of great importance in many engineering applications. The overall objective of the research reported in this dissertation is to advance the understanding and modeling of ductile fracture in metals. This research addresses three main issues: micromechanical modeling of ductile fracture, the development of a micromechanics-based ductile fracture model and its numerical implementation, and a numerical investigation of geometry and damage induced strain localization based on a nonlocal formulation. It has long been recognized that stress triaxiality is a key parameter affecting initiation of ductile fracture. More recently, shear stress has been identified as another important parameter, in addition to stress triaxiality, that influences the process of ductile fracture. In this research, a micromechanics-based model is proposed for predicting initiation of ductile fracture that couples both stress triaxiality and shear stress. The new model is based on a combination of the existing Rice-Tracey and modified maximum shear stress models. The new model is applied to construct the fracture locus of different types of metal alloys and is used to predict fracture initiation by numerical tools. The predicted results are in good agreement with experimental data reported in literature that covers a wide range of triaxialities and shear stress. Another portion of this research, within the framework of micromechanics, investigated the effect of combined normal and shear stress components on micro-void evolution and material behavior. This work involved finite element modeling of a cubic unit cell associated with a spherical void. The results show that the void growth process and macroscopic stress-strain response is highly dependent on the shear stress component. At different ranges of triaxialities, and with different void growth and coalescence mechanisms, shear stress has an important effect on the ductile fracture process. Numerical modeling of strain localization in ductile metals based on standard continuum mechanics exhibits non-convergent mesh sensitivity. This issue is addressed in the final portion of this research. A one-dimensional model based on the nonlocal theory is proposed to analyze geometry-induced strain localization, i.e., necking in structural metals. A nonlocal continuum damage model using the same enhanced continuum law is developed to deal with the damage induced strain localization in metals. Both models provide encouraging performance in eliminating the non-convergent mesh sensitivity problem. Such improved strain localization modeling techniques show potential to be useful for further exploration of ductile fracture phenomena.

Download or read book State of the Art and Future Trends in Material Modeling written by Holm Altenbach and published by Springer Nature. This book was released on 2019-10-23 with total page 505 pages. Available in PDF, EPUB and Kindle. Book excerpt: This special anniversary book celebrates the success of this Springer book series highlighting materials modeling as the key to developing new engineering products and applications. In this 100th volume of “Advanced Structured Materials”, international experts showcase the current state of the art and future trends in materials modeling, which is essential in order to fulfill the demanding requirements of next-generation engineering tasks.

Download or read book Numerical Modelling and Simulation of Metal Processing written by Christof Sommitsch and published by MDPI. This book was released on 2021-08-16 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with metal processing and its numerical modelling and simulation. In total, 21 papers from different distinguished authors have been compiled in this area. Various processes are addressed, including solidification, TIG welding, additive manufacturing, hot and cold rolling, deep drawing, pipe deformation, and galvanizing. Material models are developed at different length scales from atomistic simulation to finite element analysis in order to describe the evolution and behavior of materials during thermal and thermomechanical treatment. Materials under consideration are carbon, Q&T, DP, and stainless steels; ductile iron; and aluminum, nickel-based, and titanium alloys. The developed models and simulations shall help to predict structure evolution, damage, and service behavior of advanced materials.

Download or read book Local Approach to Fracture written by Clotilde Berdin and published by Presses des MINES. This book was released on 2004 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents several aspects of the local approach to fracture: damage mechanisms, experimental techniques, damage evolution law and failure criteria, modelling of damage, and numerical simulation -- Back cover.

Download or read book Advancing Numerical Simulation Tools for Ductile Fracture in Thin Metal Plates written by Rasmus Grau Andersen and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling in Engineering Using Innovative Numerical Methods for Solids and Fluids written by Laura De Lorenzis and published by Springer Nature. This book was released on 2020-02-08 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book examines innovative numerical methods for computational solid and fluid mechanics that can be used to model complex problems in engineering. It also presents innovative and promising simulation methods, including the fundamentals of these methods, as well as advanced topics and complex applications. Further, the book explores how numerical simulations can significantly reduce the number of time-consuming and expensive experiments required, and can support engineering decisions by providing data that would be very difficult, if not impossible, to obtain experimentally. It also includes chapters covering topics such as particle methods addressing particle-based materials and numerical methods that are based on discrete element formulations; fictitious domain methods; phase field models; computational fluid dynamics based on modern finite volume schemes; hybridizable discontinuous Galerkin methods; and non-intrusive coupling methods for structural models.

Download or read book TMS 2020 149th Annual Meeting Exhibition Supplemental Proceedings written by The Minerals, Metals & Materials Society and published by Springer Nature. This book was released on 2020-02-13 with total page 2046 pages. Available in PDF, EPUB and Kindle. Book excerpt: This collection presents papers from the 149th Annual Meeting & Exhibition of The Minerals, Metals & Materials Society.