Download or read book Reduced Order Constitutive Modeling of a Directionally solidified Nickel base Superalloy written by Sean Douglas Neal and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Hot section components of land-based gas turbines are subject to extremely harsh, high temperature environments and require the use of advanced materials. Directionally solidified Ni-base superalloys are often chosen as materials for these hot section components due to their excellent creep resistance and fatigue properties at high temperatures. These blades undergo complex thermomechanical loading conditions throughout their service life, and the influences of blade geometry and variable operation can make life prediction difficult. Accurate predictions of material response under thermomechanical loading conditions is essential for life prediction of these components. Complex crystal viscoplasticity models are often used to capture the behavior of Ni-base superalloys. While accurate, these models are computationally expensive and are not suitable for all phases of design. This work involves the calibration of a previously developed reduced-order, macroscale transversely isotropic viscoplasticity model to a directionally solidified Ni-base superalloy. The unified model is capable of capturing isothermal and thermomechanical responses in addition to secondary creep behavior. An extreme reduced order microstructure-sensitive constitutive model is also developed using an artificial neural network to provide a rapid first-order approximation of material response under various temperatures, rates of loading, and material orientation from the axis of solidification.

Download or read book Constitutive Modeling and Life Prediction in Ni base Superalloys written by Mahesh M. Shenoy and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Microstructural features at different scales affect the constitutive stress-strain response and the fatigue crack initiation life in Ni-base superalloys. While numerous efforts have been made in the past to experimentally characterize the effects of these features on the stress-strain response and/or the crack initiation life, there is a significant variability in the data with sometimes contradictory conclusions, in addition to the substantial costs involved in experimental testing. Computational techniques can be useful tools to better understand these effects since they are relatively inexpensive and are not restricted by the limitations in processing techniques. The effect of microstructure on the stress-strain response and the variability in fatigue life were analyzed using two Ni-base superalloys; DS GTD111 which is a directionally solidified Ni-base superalloy, and IN100 which is a polycrystalline Ni-base superalloy. Physically-based constitutive models were formulated and implemented as user material subroutines in ABAQUS using the single crystal plasticity framework which can predict the material stress-strain response with the microstructure-dependence embedded into them. The model parameters were calibrated using experimental cyclic stress-strain histories. A computational exercise was employed to quantify the influence of idealized microstructural variables on the fatigue crack initiation life. Understanding was sought regarding the most significant microstructure features using explicit modeling of the microstructure with the aim to predict the variability in fatigue crack initiation life and to guide material design for fatigue resistant microstructures. Lastly, it is noted that crystal plasticity models are often too computationally intensive if the objective is to model the macroscopic behavior of a textured or randomly oriented 3-D polycrystal in an engineering component. Homogenized constitutive models were formulated and implemented as user material subroutines in ABAQUS, which can capture the macroscale stress-strain response in both DS GTD111 and IN100. Even though the study was conducted on two specific Ni-base superalloys; DS GTD111 and IN100, the objective was to develop generic frameworks which should also be applicable to other alloy systems.

Download or read book Generic Behavior Framework of SX and DS Nickel base Superalloys with Applications to Constitutive and Life Prediction Modeling written by Firat Irmak and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Selection of materials to be used for components experiencing extreme conditions is a critical process in the design phase. Nickel-base superalloys have been frequently used for hot gas path components in the turbomachinery industry. These components are required to withstand both fatigue and creep at extreme temperatures during their service time. In general, the extreme temperature materials mostly embody polycrystalline, directionally solidified, and single crystal superalloys. It is essential for design engineers to predict accurate damage behavior and lifespan for these components to prevent catastrophic failures. This dissertation presents a new framework to represent mechanical behavior of Nickel-base superalloys under variety of loading conditions. A set of constitutive and lifing models that can be applied broadly are developed based on observed trends. Despite the development of over 30 variations of single crystal and directionally solidified Nickel-base superalloys, the behavior of these alloys nominally follows similar trends with respect to temperature and orientation. Temperature-, rate-, and orientation- dependence of these materials are studied. The goal is to eliminate extensive time and cost of experiments by creating parameters to be used in strength and life calculations for generic single crystal and directionally solidified Nickel-base alloys. In order to apply generic constants to deformation modeling, a crystal-plasticity model is modified to create stress-strain hysteresis loops. Strain, stress and multi-axial life models are developed to represent the lifing behavior of the candidate alloys under uniaxial and multiaxial environments. Tensile and low-cycle fatigue experiments are conducted to measure the accuracy of these models. Parameters for the models are built on regression fits in comparison with a comprehensive material database. This database includes elastic, plastic, creep, and fatigue properties.

Download or read book Anisotropic Constitutive Modeling for Nickel base Single Crystal Superalloys written by Michael Y. Sheh and published by . This book was released on 1988 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Rene 80 written by Amit Prakash and published by . This book was released on 1981 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy Research Abstracts written by and published by . This book was released on 1990 with total page 840 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Constitutive Modeling of a Nickel Base Superalloy written by Per Almroth and published by . This book was released on 2003 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NASA Technical Memorandum written by and published by . This book was released on 1994 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 1460 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Download or read book A Constitutive Model for the Inelastic Multiaxial Cyclic Response of a Nickel Base Superalloy Rene 80 written by V. G. Ramaswamy and published by . This book was released on 1986 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Low Cycle Fatigue and Elasto Plastic Behaviour of Materials 3 written by K.T. Rie and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 911 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceeds of the Third International Conference on Low Cycle Fatigue and Elasto-plastic Behaviour of Materials, Berlin Congress Center, Berlin, Germany, 7-11 September 1992

Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2566 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Constitutive Model for the Inelastic Multiaxial Cyclic Response of a Nickel Base Superalloy Ren 80 written by Vadakanchery Ganapahty Ramaswamy and published by . This book was released on 1986 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Metals Abstracts written by and published by . This book was released on 1998 with total page 1076 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thermomechanical Fatigue Behavior of Materials written by Huseyin Sehitoglu and published by ASTM International. This book was released on 1993 with total page 259 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Comprehensive Structural Integrity written by Ian Milne and published by Elsevier. This book was released on 2003-07-25 with total page 4647 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this major reference work is to provide a first point of entry to the literature for the researchers in any field relating to structural integrity in the form of a definitive research/reference tool which links the various sub-disciplines that comprise the whole of structural integrity. Special emphasis will be given to the interaction between mechanics and materials and structural integrity applications. Because of the interdisciplinary and applied nature of the work, it will be of interest to mechanical engineers and materials scientists from both academic and industrial backgrounds including bioengineering, interface engineering and nanotechnology. The scope of this work encompasses, but is not restricted to: fracture mechanics, fatigue, creep, materials, dynamics, environmental degradation, numerical methods, failure mechanisms and damage mechanics, interfacial fracture and nano-technology, structural analysis, surface behaviour and heart valves. The structures under consideration include: pressure vessels and piping, off-shore structures, gas installations and pipelines, chemical plants, aircraft, railways, bridges, plates and shells, electronic circuits, interfaces, nanotechnology, artificial organs, biomaterial prostheses, cast structures, mining... and more. Case studies will form an integral part of the work.

Download or read book Biaxial and Multiaxial Fatigue EGF 3 written by M. W. Brown and published by . This book was released on 1989 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 36 paper spresented in this volume were presented at the second international conference on biaxial/multiaxial fatigue.