Large Deformations of Solids: Physical Basis and Mathematical Modelling PDF Download

Author: J. Gittus
Publisher: Springer Science & Business Media
ISBN: 9400934076
Category : Technology & Engineering
Languages : en
Pages : 501

View

Book Description

Author: J.P. Boehler
Publisher: Springer Science & Business Media
ISBN: 9400968272
Category : Technology & Engineering
Languages : en
Pages : 926

View

Book Description
In 1978, the European Mechanics Committee and the French Centre National de la Recherche Scientifique agreed to the organization of an Interna tional Colloquium on the "Mechanical Behavior of Anisotropic Solids". The meeting was held at Villard-de-Lans (near Grenoble, France) from 19th to 22 nd June 1979. The Colloquium considered mechanical aspects of the anisotropy of solids, both initial and induced by permanent deformation, anisotropic hardening and damage, oriented fissuration, etc. Topics concerned mathematical, experimental and engineering aspects of the anisotropy of metals, composites, soils and rocks. The aim of the Colloquium was to bring together experimentalists, theoretecians and engineers interested in various features of mechanical anisotropy, in order to permit an interdisciplinary exchange of understanding, experience and methods. A detailed description of the scope, aim and proposed topics is contained in the Preface. The announcement of the Colloquium attracted a large number of sub mitted contributions. Conforming with the principles of Euromech Colloquia and of the Colloques Internationaux du CNRS, the accepted contributions were limited to 50 communications. A general description of the scientific program is to be found in the Preface. Five general lectures gave state-of-the-art reports concerning some areas of the behavior of anisotropic solids; the 50 communications were divided into 12 sessions dealing with specific topics (see "Contents"). In order to facilitate subsequent contact between the reader and the contributors, full addresses are given in the "List of Authors."

Author:
Publisher:
ISBN:
Category : Mechanics, Applied
Languages : en
Pages : 764

View

Book Description

Author: Peter Haasen
Publisher:
ISBN:
Category : Alloys
Languages : en
Pages : 738

View

Book Description

Author:
Publisher:
ISBN:
Category : Crystallography
Languages : fr
Pages : 780

View

Book Description

Author: Jean-Paul Boehler
Publisher:
ISBN:
Category : Anisotropy
Languages : en
Pages : 708

View

Book Description

Author: Jonas Saarimäki
Publisher: Linköping University Electronic Press
ISBN: 9176853853
Category :
Languages : en
Pages : 63

View

Book Description
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.

Author: Holm Altenbach
Publisher: Springer
ISBN: 3319317210
Category : Science
Languages : en
Pages : 456

View

Book Description
This volume is devoted to an actual topic which is the focus world-wide of various research groups. It contains contributions describing the material behavior on different scales, new existence and uniqueness theorems, the formulation of constitutive equations for advanced materials. The main emphasis of the contributions is directed on the following items - Modelling and simulation of natural and artificial materials with significant microstructure, - Generalized continua as a result of multi-scale models, - Multi-field actions on materials resulting in generalized material models, - Theories including higher gradients, and - Comparison with discrete modelling approaches

Author:
Publisher:
ISBN:
Category : Artificial satellites
Languages : en
Pages : 100

View

Book Description

Author: Hugo Wärner
Publisher: Linköping University Electronic Press
ISBN: 9176851745
Category :
Languages : en
Pages : 49

View

Book Description
The global energy consumption is increasing and together with global warming from greenhouse gas emission, create the need for more environmental friendly energy production processes. Higher efficiency of biomass power plants can be achieved by increasing temperature and pressure in the boiler section and this would increase the generation of electricity along with the reduction in emission of greenhouse gases e.g. CO2. The power generation must also be flexible to be able to follow the demands of the energy market, this results in a need for cyclic operating conditions with alternating output and multiple start-ups and shut-downs. Because of the demands of flexibility, higher temperature and higher pressure in the boiler section of future biomass power plants, the demands on improved mechanical properties of the materials of these components are also increased. Properties like creep strength, thermomechanical fatigue resistance and high temperature corrosion resistance are critical for materials used in the next generation biomass power plants. Austenitic stainless steels are known to possess such good high temperature properties and are relatively cheap compared to the nickel-base alloys, which are already operating at high temperature cyclic conditions in other applications. The behaviour of austenitic stainless steels during these widened operating conditions are not yet fully understood. The aim of this licentiate thesis is to increase the knowledge of the mechanical behaviour at high temperature cyclic conditions for austenitic stainless steels. This is done by the use of thermomechanical fatigue- and creepfatigue testing at elevated temperatures. For safety reasons, the effect of prolonged service degradation is investigated by pre-ageing before mechanical testing. Microscopy is used to investigate the microstructural development and resulting damage behaviour of the austenitic stainless steels after testing. The results show that creep-fatigue interaction damage, creep damage and oxidation assisted cracking are present at high temperature cyclic conditions. In addition, simulated service degradation resulted in a detrimental embrittling effect due to the deterioration by the microstructural evolution.