Residual Stress Distributions in Additively Manufactured Parts

Residual Stress Distributions in Additively Manufactured Parts PDF Author: Prabhat Pant
Publisher: Linköping University Electronic Press
ISBN: 917929913X
Category : Electronic books
Languages : en
Pages : 58

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Book Description
Additive manufacturing (AM) of parts using a layer by layer approach has seen a rapid increase in application for production of net shape or near-net shape complex parts, especially in the field of aerospace, automotive, etc. Due to the superiority of manufacturing complex shapes with ease in comparison to the conventional methods, interest in these kinds of processes has increased. Among various methods in AM, laser powder bed fusion (LPBF) is one of the most widely used techniques to produce metallic components. As in all manufacturing processes, residual stress (RS) generation during manufacturing is a relevant issue for the AM process. RS in AM are generated due to a high thermal gradient between subsequent layers. The impact of residual stresses can be significant for the mechanical integrity of the built parts and understanding the generation of RS and the effect of AM process parameters is therefore important for a broader implementation of AM techniques. The work presented in this licentiate thesis aims to investigate the influence of build orientation on the RS distribution in AM parts. For this purpose, L-shaped Inconel 718 parts were printed by LPBF in three different orientations, 0°, 45°, and 90°, respectively. Inconel 718 was selected because it is a superalloy widely used for making gas turbine components. In addition, IN718 has in general good weldability which renders it a good material for additive manufacturing. Residual stress distributions in the parts removed from the build plate were measured using neutron diffraction technique. A simple finite element model was developed to predict the residual stresses and the effect of RS relaxation due to the separation of the parts and build plate. The trend of residual stress distribution predicted was in good agreement with experimental results. In general, compressive RS at the part center and tensile RS near the surface were found. However, while the part printed in 0° orientation had the least amount of RS in all three principal directions of part, the part built in 90° orientation possessed the highest amount of RS in both compression and tension. The study has shown that residual stress distributions in the parts are strongly dependent on the building process. Further, it has shown that the relaxation of RS associated with the removal of the parts from the build plate after printing has a great impact on the final distribution of residual stress in the parts. These results can be used as guidelines for choosing the orientations of the part during printing.

Residual Stress Distributions in Additively Manufactured Parts

Residual Stress Distributions in Additively Manufactured Parts PDF Author: Prabhat Pant
Publisher: Linköping University Electronic Press
ISBN: 917929913X
Category : Electronic books
Languages : en
Pages : 58

Get Book Here

Book Description
Additive manufacturing (AM) of parts using a layer by layer approach has seen a rapid increase in application for production of net shape or near-net shape complex parts, especially in the field of aerospace, automotive, etc. Due to the superiority of manufacturing complex shapes with ease in comparison to the conventional methods, interest in these kinds of processes has increased. Among various methods in AM, laser powder bed fusion (LPBF) is one of the most widely used techniques to produce metallic components. As in all manufacturing processes, residual stress (RS) generation during manufacturing is a relevant issue for the AM process. RS in AM are generated due to a high thermal gradient between subsequent layers. The impact of residual stresses can be significant for the mechanical integrity of the built parts and understanding the generation of RS and the effect of AM process parameters is therefore important for a broader implementation of AM techniques. The work presented in this licentiate thesis aims to investigate the influence of build orientation on the RS distribution in AM parts. For this purpose, L-shaped Inconel 718 parts were printed by LPBF in three different orientations, 0°, 45°, and 90°, respectively. Inconel 718 was selected because it is a superalloy widely used for making gas turbine components. In addition, IN718 has in general good weldability which renders it a good material for additive manufacturing. Residual stress distributions in the parts removed from the build plate were measured using neutron diffraction technique. A simple finite element model was developed to predict the residual stresses and the effect of RS relaxation due to the separation of the parts and build plate. The trend of residual stress distribution predicted was in good agreement with experimental results. In general, compressive RS at the part center and tensile RS near the surface were found. However, while the part printed in 0° orientation had the least amount of RS in all three principal directions of part, the part built in 90° orientation possessed the highest amount of RS in both compression and tension. The study has shown that residual stress distributions in the parts are strongly dependent on the building process. Further, it has shown that the relaxation of RS associated with the removal of the parts from the build plate after printing has a great impact on the final distribution of residual stress in the parts. These results can be used as guidelines for choosing the orientations of the part during printing.

Practical Residual Stress Measurement Methods

Practical Residual Stress Measurement Methods PDF Author: Gary S. Schajer
Publisher: John Wiley & Sons
ISBN: 1118342372
Category : Technology & Engineering
Languages : en
Pages : 328

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Book Description
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

Cold-Spray Coatings

Cold-Spray Coatings PDF Author: Pasquale Cavaliere
Publisher: Springer
ISBN: 3319671839
Category : Technology & Engineering
Languages : en
Pages : 566

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Book Description
This book combines the contributions of experts in the field to describe the behavior of various materials, micromechanisms involved during processing, and the optimization of cold-spray technology. It spans production, characterization, and applications including wear resistance, fatigue, life improvement, thermal barriers, crack repair, and biological applications. Cold spray is an innovative coating technology based on the kinetic energy gained by particles sprayed at very high pressures. While the technique was developed in the 1990s, industrial and scientific interest in this technology has grown vastly in the last ten years. Recently, many interesting applications have been associated with cold-sprayed coatings, including wear resistance, fatigue life improvement, thermal barriers, biological applications, and crack repair. However, many fundamental aspects require clarification and description.

Thermo-Mechanical Modeling of Additive Manufacturing

Thermo-Mechanical Modeling of Additive Manufacturing PDF Author: Michael Gouge
Publisher: Butterworth-Heinemann
ISBN: 0128118210
Category : Technology & Engineering
Languages : en
Pages : 296

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Book Description
Thermo-mechanical Modeling of Additive Manufacturing provides the background, methodology and description of modeling techniques to enable the reader to perform their own accurate and reliable simulations of any additive process. Part I provides an in depth introduction to the fundamentals of additive manufacturing modeling, a description of adaptive mesh strategies, a thorough description of thermal losses and a discussion of residual stress and distortion. Part II applies the engineering fundamentals to direct energy deposition processes including laser cladding, LENS builds, large electron beam parts and an exploration of residual stress and deformation mitigation strategies. Part III concerns the thermo-mechanical modeling of powder bed processes with a description of the heat input model, classical thermo-mechanical modeling, and part scale modeling. The book serves as an essential reference for engineers and technicians in both industry and academia, performing both research and full-scale production. Additive manufacturing processes are revolutionizing production throughout industry. These technologies enable the cost-effective manufacture of small lot parts, rapid repair of damaged components and construction of previously impossible-to-produce geometries. However, the large thermal gradients inherent in these processes incur large residual stresses and mechanical distortion, which can push the finished component out of engineering tolerance. Costly trial-and-error methods are commonly used for failure mitigation. Finite element modeling provides a compelling alternative, allowing for the prediction of residual stresses and distortion, and thus a tool to investigate methods of failure mitigation prior to building. - Provides understanding of important components in the finite element modeling of additive manufacturing processes necessary to obtain accurate results - Offers a deeper understanding of how the thermal gradients inherent in additive manufacturing induce distortion and residual stresses, and how to mitigate these undesirable phenomena - Includes a set of strategies for the modeler to improve computational efficiency when simulating various additive manufacturing processes - Serves as an essential reference for engineers and technicians in both industry and academia

Introduction to the Characterization of Residual Stress by Neutron Diffraction

Introduction to the Characterization of Residual Stress by Neutron Diffraction PDF Author: M.T. Hutchings
Publisher: CRC Press
ISBN: 0203402812
Category : Science
Languages : en
Pages : 383

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Book Description
Over the past 25 years the field of neutron diffraction for residual stress characterization has grown tremendously, and has matured from the stage of trial demonstrations to provide a practical tool with widespread applications in materials science and engineering. While the literature on the subject has grown commensurately, it has also remained

Proceedings of the 13th World Conference on Titanium

Proceedings of the 13th World Conference on Titanium PDF Author: Vasisht Venkatesh
Publisher: John Wiley & Sons
ISBN: 1119296110
Category : Technology & Engineering
Languages : en
Pages : 4024

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Book Description
This book contains the Proceedings of the 13th World Conference on Titanium.

Metal Additive Manufacturing

Metal Additive Manufacturing PDF Author: Dyuti Sarker
Publisher: John Wiley & Sons
ISBN: 1119210836
Category : Science
Languages : en
Pages : 624

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Book Description
METAL ADDITIVE MANUFACTURING A comprehensive review of additive manufacturing processes for metallic structures Additive Manufacturing (AM)—also commonly referred to as 3D printing—builds three-dimensional objects by adding materials layer by layer. Recent years have seen unprecedented investment in additive manufacturing research and development by governments and corporations worldwide. This technology has the potential to replace many conventional manufacturing processes, enable the development of new industry practices, and transform the entire manufacturing enterprise. Metal Additive Manufacturing provides an up-to-date review of all essential physics of metal additive manufacturing techniques with emphasis on both laser-based and non-laser-based additive manufacturing processes. This comprehensive volume covers fundamental processes and equipment, governing physics and modelling, design and topology optimization, and more. The text adresses introductory, intermediate, and advanced topics ranging from basic additive manufacturing process classification to practical and material design aspects of additive manufacturability. Written by a panel of expert authors in the field, this authoritative resource: Provides a thorough analysis of AM processes and their theoretical foundations Explains the classification, advantages, and applications of AM processes Describes the equipment required for different AM processes for metallic structures, including laser technologies, positioning devices, feeder and spreader mechanisms, and CAD software Discusses the opportunities, challenges, and current and emerging trends within the field Covers practical considerations, including design for AM, safety, quality assurance, automation, and real-time control of AM processes Includes illustrative cases studies and numerous figures and tables Featuring material drawn from the lead author’s research and professional experience on laser additive manufacturing, Metal Additive Manufacturing is an important source for manufacturing professionals, research and development engineers in the additive industry, and students and researchers involved in mechanical, mechatronics, automatic control, and materials engineering and science.

Welding Deformation and Residual Stress Prevention

Welding Deformation and Residual Stress Prevention PDF Author: Yukio Ueda
Publisher: Elsevier
ISBN: 0123948045
Category : Architecture
Languages : en
Pages : 313

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Book Description
Preface 1 Introduction to welding mechanics 2 Measurement and prediction of residual stresses by inherent strain method 3 Basic knowledge on simulation analysis for welding thermal process, stress and deformation 4. Basic Concept of Finite Element Method 5 Questions and Answers of attached FEM programs 6 Experience simulation using attached FEM programs 7 Simulation Analysis of welding stresses and deformation for manufacturing problems Appendix A Tables and figures of welding residual stresses in various welded joints Appendix B Temperature dependent material properties and samples for FEM simulation Appendix C Three dimensional mathematical equations for thermal elastic plastic creep phenomena.

Residual Stresses 2018

Residual Stresses 2018 PDF Author: Marc Seefeldt
Publisher: Materials Research Forum LLC
ISBN: 1945291893
Category : Technology & Engineering
Languages : en
Pages : 310

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Book Description
The European Conference on Residual Stresses (ECRS) series is the leading European forum for scientific exchange on internal and residual stresses in materials. It addresses both academic and industrial experts and covers a broad gamut of stress-related topics from instrumentation via experimental and modelling methodology up to stress problems in specific processes such as welding or shot-peening, and their impact on materials properties. Chapters: Diffraction Methods; Mechanical Relaxation Methods; Acoustic and Electromagnetic Methods; Composites, Nano and Microstructures; Films, Coatings and Oxides; Cold Working and Machining; Heat Treatments and Phase Transformations; Welding, Fatigue and Fracture: Stresses in Additive Manufacturing.

Residual Stress, Thermomechanics & Infrared Imaging and Inverse Problems, Volume 6

Residual Stress, Thermomechanics & Infrared Imaging and Inverse Problems, Volume 6 PDF Author: Antonio Baldi
Publisher: Springer Nature
ISBN: 3030300986
Category : Science
Languages : en
Pages : 167

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Book Description
Residual Stress, Thermomechanics & Infrared Imaging and Inverse Problems, Volume 6 of the Proceedings of the 2019 SEM Annual Conference & Exposition on Experimental and Applied Mechanics, the sixth volume of six from the Conference, brings together contributions to this important area of research and engineering. The collection presents early findings and case studies on a wide range of areas, including: Test Design and Inverse Method Algorithms Inverse Problems: Virtual Fields Method Residual Stresses: Measurement, Uncertainty & Validation Residual Stresses: Eigenvalues, Modeling, & Crack Growth Material Characterizations Using Thermography Fatigue, Damage & Fracture Evaluation Using Infrared Thermography