The Measurement of Crack Tip Stresses by X-ray Diffraction

The Measurement of Crack Tip Stresses by X-ray Diffraction PDF Author: John Edmond Allison
Publisher:
ISBN:
Category : Fracture mechanics
Languages : en
Pages : 136

Get Book Here

Book Description
To ensure the structural integrity of present day structures subjected to variable amplitude cyclic stress histories, a knowledge of the crack tip stress field is important. In this investigation, crack tip stresses were measured in specimens of 1020 and 1045 steel using a semi-automatic x-ray diffraction technique. Crack tip residual stresses were measured in the unloaded condition and crack tip 'applied' stresses were measured under load. It was observed that, for the alloys tested and within the confines of stress analysis by x-ray diffraction, a dependence exists for the maximum crack tip residual stress on the level of the previous stress intensity factor and also for the maximum crack tip 'applied' stress on the level of the applied stress intensity. This is in sharp contrast to theoretical models of the crack tip stress fields which predict an independence between crack tip stresses and stress intensity levels. Crack tip stresses were observed relative to the fatigue crack growth retardation process. Post overload crack tip stresses were greatly reduced from their pre-overload levels. Limited studies indicated that crack growth, after an overload, had little or no effect on the overload-induced crack tip residual stress distribution. Measurements taken at applied loads, indicated that portions of the material behind the tip of the extended crack were in compression while areas ahead of the extended crack were in tension. These results were considered in light of possible retardation mechanisms.

The Measurement of Crack Tip Stresses by X-ray Diffraction

The Measurement of Crack Tip Stresses by X-ray Diffraction PDF Author: John Edmond Allison
Publisher:
ISBN:
Category : Fracture mechanics
Languages : en
Pages : 136

Get Book Here

Book Description
To ensure the structural integrity of present day structures subjected to variable amplitude cyclic stress histories, a knowledge of the crack tip stress field is important. In this investigation, crack tip stresses were measured in specimens of 1020 and 1045 steel using a semi-automatic x-ray diffraction technique. Crack tip residual stresses were measured in the unloaded condition and crack tip 'applied' stresses were measured under load. It was observed that, for the alloys tested and within the confines of stress analysis by x-ray diffraction, a dependence exists for the maximum crack tip residual stress on the level of the previous stress intensity factor and also for the maximum crack tip 'applied' stress on the level of the applied stress intensity. This is in sharp contrast to theoretical models of the crack tip stress fields which predict an independence between crack tip stresses and stress intensity levels. Crack tip stresses were observed relative to the fatigue crack growth retardation process. Post overload crack tip stresses were greatly reduced from their pre-overload levels. Limited studies indicated that crack growth, after an overload, had little or no effect on the overload-induced crack tip residual stress distribution. Measurements taken at applied loads, indicated that portions of the material behind the tip of the extended crack were in compression while areas ahead of the extended crack were in tension. These results were considered in light of possible retardation mechanisms.

Fracture Mechanics

Fracture Mechanics PDF Author: Thomas A. Cruse
Publisher: ASTM International
ISBN:
Category : Fracture mechanics
Languages : en
Pages : 796

Get Book Here

Book Description


Fracture Mechanics

Fracture Mechanics PDF Author: National Symposium on Fracture Mechanics
Publisher: ASTM International
ISBN: 9780803103641
Category : Technology & Engineering
Languages : en
Pages : 808

Get Book Here

Book Description


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

Get Book Here

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

Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 602

Get Book Here

Book Description
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.

Fracture, Fatigue, Failure and Damage Evolution, Volume 6

Fracture, Fatigue, Failure and Damage Evolution, Volume 6 PDF Author: Jay Carroll
Publisher: Springer
ISBN: 3319958798
Category : Science
Languages : en
Pages : 112

Get Book Here

Book Description
Fracture, Fatigue, Failure and Damage Evolution, Volume 6 of the Proceedings of the 2018 SEM Annual Conference & Exposition on Experimental and Applied Mechanics, the sixth volume of eight 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: Novel Experimental Methods Extreme Environments Interfacial Fracture Integration of Models & Experiments Mechanics of Energy & Energetic Materials Integration of Models & Experiments In Situ Techniques for Fatigue & Fracture Microscale & Microstructural Effects on Mechanical Behavior

Technical Abstract Bulletin

Technical Abstract Bulletin PDF Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 1186

Get Book Here

Book Description


Government Reports Announcements & Index

Government Reports Announcements & Index PDF Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 1022

Get Book Here

Book Description


Residual Stress, Thermomechanics & Infrared Imaging, Hybrid Techniques and Inverse Problems, Volume 7

Residual Stress, Thermomechanics & Infrared Imaging, Hybrid Techniques and Inverse Problems, Volume 7 PDF Author: Antonio Baldi
Publisher: Springer
ISBN: 3319950746
Category : Science
Languages : en
Pages : 125

Get Book Here

Book Description
Residual Stress, Thermomechanics & Infrared Imaging, Hybrid Techniques and Inverse Problems, Volume 7 of the Proceedings of the 2018 SEM Annual Conference & Exposition on Experimental and Applied Mechanics, the seventh volume of eight 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: Inverse Problems/Hybrid Techniques Material Characterizations Using Thermography Thermoelastic Stress Analysis Fatigue & Damage Evaluation Using Infrared Thermography Integration of Infrared Thermography & DIC Thermographic Non-Destructive Evaluation (NDE)

Elastic-plastic Fracture Test Methods

Elastic-plastic Fracture Test Methods PDF Author: James Albert Joyce
Publisher: ASTM International
ISBN: 0803114184
Category : Elasticity
Languages : en
Pages : 351

Get Book Here

Book Description