Download or read book Modeling of High strain rate Deformation Fracture and Impact Behavior of Advanced Gas Turbine Engine Materials Nasa cr 2003 212194 written by United States. National Aeronautics and Space Administration and published by . This book was released on 2003* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling of High Strain Rate Deformation Fracture and Impact Behavior of Advanced Gas Turbine Engine Materials at Low and Elevated Temperatures written by and published by DIANE Publishing. This book was released on 2003 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Explicit Finite Element Modeling of Multilayer Composite Fabric for Gas Turbine Engine Containment Systems Part 2 Ballistic Impact Testing written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-05-31 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Under the Federal Aviation Administration's Airworthiness Assurance Center of Excellence and the Aircraft Catastrophic Failure Prevention Program, National Aeronautics and Space Administration Glenn Research Center collaborated with Arizona State University, Honeywell Engines, Systems and Services, and SRI International to develop improved computational models for designing fabric-based engine containment systems. In the study described in this report, ballistic impact tests were conducted on layered dry fabric rings to provide impact response data for calibrating and verifying the improved numerical models. This report provides data on projectile velocity, impact and residual energy, and fabric deformation for a number of different test conditions.Pereira, J. M. and Revilock, D. M.Glenn Research CenterCONTAINMENT; FABRICS; GAS TURBINE ENGINES; BALLISTICS; COMPOSITE MATERIALS; FINITE ELEMENT METHOD; AIRCRAFT RELIABILITY; ENGINE PARTS; IMPACT TESTS; NASA PROGRAMS; PROJECTILES; FAN BLADES; DEFORMATION; RESIDUAL STRESS
Download or read book Cracks in superalloys written by Jonas Saarimäki and published by Linköping University Electronic Press. This book was released on 2018-01-18 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gas turbines are widely used in industry for power generation and as a power source at hard to reach locations where other possibilities for electrical power supplies are insufficient. New ways of producing greener energy is needed to reduce emission levels. This can be achieved by increasing the combustion temperature of gas turbines. High combustion temperatures can be detrimental and degrade critical components. This raises the demands on the high temperature performance of the superalloys used in gas turbine components. These components are frequently subjected to different cyclic loads combined with for example dwell-times and overloads at elevated temperatures, which can influence the crack growth. Dwell-times have been shown to accelerate crack growth and change cracking behaviour in both Inconel 718, Haynes 282 and Hastelloy X. On the other hand, overloads at the beginning of a dwell-time cycle have been shown to retard the dwell-time effect on crack growth in Inconel 718. More experiments and microstructural investigations are needed to better understand these effects. The work presented in this thesis was conducted under the umbrella of the research program Turbo Power; "High temperature fatigue crack propagation in nickel-based superalloys", where I have mainly looked at fatigue crack growth mechanisms in superalloys subjected to dwell-fatigue, which can have a devastating effect on crack propagation behaviour. Mechanical testing was performed under operation-like cycles in order to achieve representative microstructures and material data for the subsequent microstructural work. Microstructures were investigated using light optical microscopy and scanning electron microscopy (SEM) techniques such as electron channeling contrast imaging (ECCI) and electron backscatter diffraction (EBSD). The outcome of this work has shown that there is a significant increase in crack growth rate when dwell-times are introduced at maximum load (0 % overload) in the fatigue cycle. With the introduction of a dwell-time there is also a shift from transgranular to intergranular crack growth for both Inconel 718 and Haynes 282. The crack growth rate decreases with increasing overload levels in Inconel 718 when an overload is applied prior to the dwell-time. At high temperature, intergranular crack growth was observed in Inconel 718 as a result of oxidation and the creation of nanometric voids. Another observed growth mechanism was crack advance along ?-phase boundaries with subsequent oxidation of the ?-phase. This thesis comprises two parts. Part I gives an introduction to the field of superalloys and the acting microstructural mechanisms related to fatigue and crack propagation. Part II consists of five appended papers, which report the work completed as part of the project.
Download or read book Effect of Dwell times on Crack Propagation in Superalloys written by Jonas Saarimäki and published by Linköping University Electronic Press. This book was released on 2015-12-10 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gas turbines are widely used in industry for power generation and as a power source at "hard to reach" locations where other possibilities for electrical supply are insufficient. There is a strong need for greener energy, considering the effect that pollution has had on global warming, and we need to come up with ways of producing cleaner electricity. A way to achieve this is by increasing the combustion temperature in gas turbines. This increases the demand on the high temperature performance of the materials used e.g. superalloys in the turbine. These high combustion temperatures can lead to detrimental degradation of critical components. These components are commonly subjected to cyclic loading of different types e.g. combined with dwell-times and overloads at elevated temperatures, which influence the crack growth. Dwell-times have shown to accelerate crack growth and change the cracking behaviour in both Inconel 718 and Haynes 282. Overloads at the beginning of the dwell-time cycle have shown to retard the dwell time effect on crack growth in Inconel 718. To understand these effects more microstructural investigations are needed. The work presented in this licentiate thesis was conducted under the umbrella of the research program Turbo Power; "High temperature fatigue crack propagation in nickel-based superalloys", concentrating on fatigue crack growth mechanisms in superalloys during dwell-times, which have shown to have a devastating effect on the crack propagation behaviour. Mechanical testing was performed under operation-like conditions in order to achieve representative microstructures and material data for the subsequent microstructural work. The microstructures were microscopically investigated in a scanning electron microscope (SEM) using electron channeling contrast imaging (ECCI) as well as using light optical microscopy. The outcome of this work has shown that there is a significant increase in crack growth rate when dwell-times are introduced at the maximum load (0% overload) in the fatigue cycle. With the introduction of a dwell-time there is also a shift from transgranular to intergranular crack growth for both Inconel 718 and Haynes 282. When an overload is applied prior to the dwell-time, the crack growth rate decreases with increasing overload levels in Inconel 718. At high temperature crack growth in Inconel 718 took place as intergranular crack growth along grain boundaries due to oxidation and the creation of nanometric voids. Another observed growth mechanism was crack advance along phase boundaries with subsequent severe oxidation of the phase. This thesis comprises two parts. The first giving an introduction to the field of superalloys and the acting microstructural mechanisms that influence fatigue during dwell times. The second part consists of two appended papers, which report the work completed so far in the project.
Download or read book Advanced Materials and Processes for Gas Turbines written by Gerhard E. Fuchs and published by Minerals, Metals, & Materials Society. This book was released on 2003 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: Materials issues for the design of industrial gas turbines/Henderson MB., Hannis J., McColvin G. and Ogle G., pp. 3.
Download or read book Effect of Strain Rate on the Ductile Fracture of Advanced High Strength Steel Sheets written by Matthieu Dunand and published by . This book was released on 2013 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Strain Rate Compression Testing of Ceramics and Ceramic Composites written by and published by . This book was released on 2005 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: The compressive deformation and failure behavior of ceramics and ceramic-metal composites for armor applications has been studied as a function of strain rate at Los Alamos National Laboratory since the late 1980s. High strain rate ((almost equal to)103 s−1) uniaxial compression loading can be achieved using the Kolsky-split-Hopkinson pressure bar (SHPB) technique, but special methods must be used to obtain valid strength results. This paper reviews these methods and the limitations of the Kolsky-SHPB technique for this class of materials. The Kolsky-split-Hopkinson pressure bar (Kolsky-SHPB) technique was originally developed to characterize the mechanical behavior of ductile materials such as metals and polymers where the results can be used to develop strain-rate and temperature-dependent constitutive behavior models that empirically describe macroscopic plastic flow. The flow behavior of metals and polymers is generally controlled by thermally-activated and rate-dependent dislocation motion or polymer chain motion in response to shear stresses. Conversely, the macroscopic mechanical behavior of dense, brittle, ceramic-based materials is dominated by elastic deformation terminated by rapid failure associated with the propagation of defects in the material in response to resolved tensile stresses. This behavior is usually characterized by a distribution of macroscopically measured failure strengths and strains. The basis for any strain-rate dependence observed in the failure strength must originate from rate-dependence in the damage and fracture process, since uniform, uniaxial elastic behavior is rate-independent (e.g. inertial effects on crack growth). The study of microscopic damage and fracture processes and their rate-dependence under dynamic loading conditions is a difficult experimental challenge that is not addressed in this paper. The purpose of this paper is to review the methods that have been developed at the Los Alamos National Laboratory to perform valid, uniaxial, dynamic compression experiments on brittle materials using the Kolsky-SHPB technique and to emphasize the limitations of this technique. Kolsky-SHPB results for several ceramic and ceramic-metal(cermet) materials of interest for armor applications have been measured and show little or no strain rate sensitivity compared to quasi-static compression results.
Download or read book Fatigue Characterization of Alloy 10 written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-05-31 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: A detailed fatigue characterization of Alloy 10, a high strength nickel-based disk alloy, was conducted on test coupons machined from a 'pancake' forging. Smooth bar, strain controlled fatigue testing at various R-ratios was run at representative bore, 750 F, and rim, 1300 F, temperatures. This was followed by notch fatigue testing (Kt=2) run under load control. Analysis of the fatigue data using a Smith-Watson-Topper approach and finite element analysis of the notch root was employed to understand material behavior in these tests. Smooth bar fatigue data showed a significant R-ratio dependence at either test temperature which could be accounted for using a Smith-Watson-Topper parameter (SWT). In general, fatigue life was longer at 750 F than 1300 F for a given SWT. For notch fatigue tests, life was longer at 750 F than 1300 F but only at higher stresses. This was attributed to differences in alloy strength. At lower stresses, finite element analysis suggested that convergence of fatigue life at both temperatures resulted from relaxation of stresses at the notch root in the 1300 F tests.Gayda, JohnGlenn Research CenterFATIGUE (MATERIALS); FATIGUE LIFE; FATIGUE TESTS; HIGH STRENGTH ALLOYS; NICKEL ALLOYS; ENGINE DESIGN; FINITE ELEMENT METHOD; NOTCH TESTS
Download or read book High Shear Strain Rate Behavior of W Ni Fe Tungsten Heavy Alloy Composites as a Function of Matrix Volume Fraction written by and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of matrix volume fraction on the high shear strain-rate deformation and failure behavior of W-Ni-Fe heavy alloys is studied using the torsional Hopkinson bar apparatus. High strain-rate tests (at 700/s) were conducted using torsion specimens made from W-Ni-Fe alloys with three different matrix volume fractions. Different matrix volume fractions were obtained by changing the W content in the W-Ni-Fe alloy while keeping W grain size approximately constant. Experimental observations indicate that as the matrix volume fraction is decreased, the strain to failure decreases, at high rates of loading. There were no significant changes seen in the deformation behavior of the three materials at high shear strain-rate loading used in this study.
Download or read book Handbook of Engineering Practice of Materials and Corrosion written by Jung-Chul (Thomas) Eun and published by Springer Nature. This book was released on 2020-09-04 with total page 885 pages. Available in PDF, EPUB and Kindle. Book excerpt: This handbook is an in-depth guide to the practical aspects of materials and corrosion engineering in the energy and chemical industries. The book covers materials, corrosion, welding, heat treatment, coating, test and inspection, and mechanical design and integrity. A central focus is placed on industrial requirements, including codes, standards, regulations, and specifications that practicing material and corrosion engineers and technicians face in all roles and in all areas of responsibility. The comprehensive resource provides expert guidance on general corrosion mechanisms and recommends materials for the control and prevention of corrosion damage, and offers readers industry-tested best practices, rationales, and case studies.
Download or read book High Velocity Impact Dynamics written by Jonas A. Zukas and published by Wiley-Interscience. This book was released on 1990-11-08 with total page 968 pages. Available in PDF, EPUB and Kindle. Book excerpt: This compendium of mathematical techniques for the modeling and simulation of high-velocity impacts presents the various analytical and experimental aspects of impact dynamics and describes the responses of a variety of materials and structures under impact. Coverage is extended beyond that of the author's Impact Dynamics and deals with new topics in impacts involving inert materials, including the dynamic response to energetic and inert materials. Treatment uses classical mechanics along with the conservation laws, combined with failure analysis.
