Author: Ross Beesley
Publisher:
ISBN:
Category :
Languages : en
Pages : 484
Book Description
Structural integrity is a vitally important field of engineering with fracture and fatigue causing the vast majority of mechanical failures. This is of particular importance within the power industry where the consequences of failure can be severe. Power plant components may contain complex geometries and critical features which can introduce stress concentrations, and are often subject to complex cyclic loading histories. Consequently,fatigue is a dominant failure mechanism which can limit the component life.This research is targeted towards industrial gas turbines, with a specific application to nozzle guide vanes, in which, the extreme temperatures involved induce great thermal loading, compromising their integrity. To this end, extensive development is continually performed to carefully balance their thermal and structural requirements. However,there is still a need to improve understanding of these complex stress distributions.Conventional fatigue life assessment methods can be overly simplistic and tend to offer a one-size-fits-all approach, potentially providing overly conservative values of fatigue life. More realistic methods with improved levels of accuracy are therefore needed. This highlights the requirement for more bespoke techniques that can offer a greater understanding of the stress distributions in these complex components and high specification materials. During the development of such bespoke methods, it is important that they are readily accessible for routine use within engineering, by providing a user-friendly step-by-step approach. This industrial sponsored research aims to address these issues and provide a turn-key solution.Included in this procedure, are two novel methodologies which have been developed during the course of this work. These are the Reversed Plasticity Domain Method for the determination of the critical loads to cause low cycle fatigue failure, and the Modified Monotonic Loading Concept for the calculation of the cyclic J-integral.
Crack Growth Modelling from Stress Concentrations Under Cyclic Loading Histories
Author: Ross Beesley
Publisher:
ISBN:
Category :
Languages : en
Pages : 484
Book Description
Structural integrity is a vitally important field of engineering with fracture and fatigue causing the vast majority of mechanical failures. This is of particular importance within the power industry where the consequences of failure can be severe. Power plant components may contain complex geometries and critical features which can introduce stress concentrations, and are often subject to complex cyclic loading histories. Consequently,fatigue is a dominant failure mechanism which can limit the component life.This research is targeted towards industrial gas turbines, with a specific application to nozzle guide vanes, in which, the extreme temperatures involved induce great thermal loading, compromising their integrity. To this end, extensive development is continually performed to carefully balance their thermal and structural requirements. However,there is still a need to improve understanding of these complex stress distributions.Conventional fatigue life assessment methods can be overly simplistic and tend to offer a one-size-fits-all approach, potentially providing overly conservative values of fatigue life. More realistic methods with improved levels of accuracy are therefore needed. This highlights the requirement for more bespoke techniques that can offer a greater understanding of the stress distributions in these complex components and high specification materials. During the development of such bespoke methods, it is important that they are readily accessible for routine use within engineering, by providing a user-friendly step-by-step approach. This industrial sponsored research aims to address these issues and provide a turn-key solution.Included in this procedure, are two novel methodologies which have been developed during the course of this work. These are the Reversed Plasticity Domain Method for the determination of the critical loads to cause low cycle fatigue failure, and the Modified Monotonic Loading Concept for the calculation of the cyclic J-integral.
Publisher:
ISBN:
Category :
Languages : en
Pages : 484
Book Description
Structural integrity is a vitally important field of engineering with fracture and fatigue causing the vast majority of mechanical failures. This is of particular importance within the power industry where the consequences of failure can be severe. Power plant components may contain complex geometries and critical features which can introduce stress concentrations, and are often subject to complex cyclic loading histories. Consequently,fatigue is a dominant failure mechanism which can limit the component life.This research is targeted towards industrial gas turbines, with a specific application to nozzle guide vanes, in which, the extreme temperatures involved induce great thermal loading, compromising their integrity. To this end, extensive development is continually performed to carefully balance their thermal and structural requirements. However,there is still a need to improve understanding of these complex stress distributions.Conventional fatigue life assessment methods can be overly simplistic and tend to offer a one-size-fits-all approach, potentially providing overly conservative values of fatigue life. More realistic methods with improved levels of accuracy are therefore needed. This highlights the requirement for more bespoke techniques that can offer a greater understanding of the stress distributions in these complex components and high specification materials. During the development of such bespoke methods, it is important that they are readily accessible for routine use within engineering, by providing a user-friendly step-by-step approach. This industrial sponsored research aims to address these issues and provide a turn-key solution.Included in this procedure, are two novel methodologies which have been developed during the course of this work. These are the Reversed Plasticity Domain Method for the determination of the critical loads to cause low cycle fatigue failure, and the Modified Monotonic Loading Concept for the calculation of the cyclic J-integral.
Comprehensive Structural Integrity: Cyclic loading and fatigue
Author: I. Milne
Publisher: Elsevier
ISBN: 0080441556
Category : Technology & Engineering
Languages : en
Pages : 539
Book Description
Publisher: Elsevier
ISBN: 0080441556
Category : Technology & Engineering
Languages : en
Pages : 539
Book Description
Cyclic Stress-Strain and plastic deformation Aspects of fatigue crack growth
Author: L. F. Impellizzeri
Publisher: ASTM International
ISBN:
Category : Aluminum alloys
Languages : en
Pages : 234
Book Description
Publisher: ASTM International
ISBN:
Category : Aluminum alloys
Languages : en
Pages : 234
Book Description
Prediction of Fatigue-crack Growth Under Variableamplitude and Spectrum Loading Using a Closure Model
Elastic-plastic Fatigue Crack Growth Analysis Under Variable Amplitude Loading Spectra
Author: Semen Mikheevskiy
Publisher:
ISBN:
Category :
Languages : en
Pages : 149
Book Description
Most components or structures experience in service a variety of cyclic stresses. In the case of cyclic constant amplitude loading the fatigue crack growth depends only on the crack, the component geometry and the applied loading. In the case of variable amplitude loading it also depends on the preceding cyclic loading history. Various types of load sequence (overloads, under-loads, or combination of them) may induce different load-interaction effects which can cause either acceleration or reduction of the fatigue crack growth rate. The previously developed UniGrow fatigue crack growth model for constant amplitude loading histories which was based on the analysis of the local stress-strain material behaviour at the crack tip has been improved, modified and extended to such a level of sophistication that it can be used for fatigue crack growth analyses of cracked bodies subjected to arbitrary variable amplitude loading spectra. It was shown that the UniGrow model enables to correctly predict the effect of the applied compressive stress and tensile overloads by accounting for the existence of the internal (residual) stresses induced by the reversed cyclic plasticity around the crack tip. This idea together with additional structural memory effect model has been formalized mathematically and coded into computer program convenient for predicting fatigue crack growth under arbitrary variable amplitude loading spectra.
Publisher:
ISBN:
Category :
Languages : en
Pages : 149
Book Description
Most components or structures experience in service a variety of cyclic stresses. In the case of cyclic constant amplitude loading the fatigue crack growth depends only on the crack, the component geometry and the applied loading. In the case of variable amplitude loading it also depends on the preceding cyclic loading history. Various types of load sequence (overloads, under-loads, or combination of them) may induce different load-interaction effects which can cause either acceleration or reduction of the fatigue crack growth rate. The previously developed UniGrow fatigue crack growth model for constant amplitude loading histories which was based on the analysis of the local stress-strain material behaviour at the crack tip has been improved, modified and extended to such a level of sophistication that it can be used for fatigue crack growth analyses of cracked bodies subjected to arbitrary variable amplitude loading spectra. It was shown that the UniGrow model enables to correctly predict the effect of the applied compressive stress and tensile overloads by accounting for the existence of the internal (residual) stresses induced by the reversed cyclic plasticity around the crack tip. This idea together with additional structural memory effect model has been formalized mathematically and coded into computer program convenient for predicting fatigue crack growth under arbitrary variable amplitude loading spectra.
Mechanics of Crack Growth
Author: National Symposium on Fracture Mechanics (8th : 1974 : Brown University)
Publisher: ASTM International
ISBN:
Category :
Languages : en
Pages : 507
Book Description
Publisher: ASTM International
ISBN:
Category :
Languages : en
Pages : 507
Book Description
Scientific and Technical Aerospace Reports
Mechanics of Crack Growth
Author: J. R. Rice
Publisher: ASTM International
ISBN: 9780803105096
Category : Technology & Engineering
Languages : en
Pages : 516
Book Description
Publisher: ASTM International
ISBN: 9780803105096
Category : Technology & Engineering
Languages : en
Pages : 516
Book Description
Measurement and Analysis of Critical Crack Tip Processes During Fatigue Crack Growth
Correlation Between Numerically Predicted Crack Opening Load and Measured Load History Dependent Crack Growth Threshold
Author: L. Anquez
Publisher:
ISBN:
Category : Crack closure
Languages : en
Pages : 18
Book Description
The present paper deals with the application of a two-dimensional (plane stress) elastoplastic (Prager's flow rule) finite--element analysis to predict crack opening stresses during the crack growth process under cyclic loading. The main results obtained are as follows:.
Publisher:
ISBN:
Category : Crack closure
Languages : en
Pages : 18
Book Description
The present paper deals with the application of a two-dimensional (plane stress) elastoplastic (Prager's flow rule) finite--element analysis to predict crack opening stresses during the crack growth process under cyclic loading. The main results obtained are as follows:.