Elastic Plastic Fracture Mechanics Methodology For Surface Cracks

Elastic Plastic Fracture Mechanics Methodology for Surface Cracks PDF
Author: National Aeronautics and Space Adm Nasa
Publisher: Independently Published
ISBN: 9781730943621
Size: 74.24 MB
Format: PDF, Kindle
Category : Science
Languages : en
Pages : 96
View: 2907

Get Book

The Elastic Plastic Fracture Mechanics Methodology has evolved significantly in the last several years. Nevertheless, some of these concepts need to be extended further before the whole methodology can be safely applied to structural parts. Specifically, there is a need to include the effect of constraint in the characterization of material resistance to crack growth and also to extend these methods to the case of 3D defects. As a consequence, this project was started as a 36 month research program with the general objective of developing an elastic plastic fracture mechanics methodology to assess the structural reliability of pressure vessels and other parts of interest to NASA which may contain flaws. The project is divided into three tasks that deal with (1) constraint and thickness effects, (2) three-dimensional cracks, and (3) the Leak-Before-Burst (LBB) criterion. This report period (March 1994 to August 1994) is a continuation of attempts to characterize three dimensional aspects of fracture present in 'two dimensional' or planar configuration specimens (Chapter Two), especially, the determination of, and use of, crack face separation data. Also, included, are a variety of fracture resistance testing results (J(m)R-curve format) and a discussion regarding two materials of NASA interest (6061-T651 Aluminum alloy and 1N718-STA1 nickel-base super alloy) involving a bases for like constraint in terms of ligament dimensions, and their comparison to the resulting J(m)R-curves (Chapter Two). Ernst, Hugo A. and Lambert, D. M. Unspecified Center...

Elastic Plastic Fracture Mechanics Analysis Of Critical Flaw Size In Ares I X Flange To Skin Welds

Elastic Plastic Fracture Mechanics Analysis of Critical Flaw Size in Ares I X Flange To Skin Welds PDF
Author: National Aeronautics and Space Adm Nasa
Publisher: Independently Published
ISBN: 9781793938459
Size: 62.10 MB
Format: PDF
Category : Science
Languages : en
Pages : 42
View: 3499

Get Book

NASA's Ares 1 Upper Stage Simulator (USS) is being fabricated from welded A516 steel. In order to insure the structural integrity of these welds it is of interest to calculate the critical initial flaw size (CIFS) to establish rational inspection requirements. The CIFS is in turn dependent on the critical final flaw size (CFS), as well as fatigue flaw growth resulting from transportation, handling and service-induced loading. These calculations were made using linear elastic fracture mechanics (LEFM), which are thought to be conservative because they are based on a lower bound, so called elastic, fracture toughness determined from tests that displayed significant plasticity. Nevertheless, there was still concern that the yield magnitude stresses generated in the flange-to-skin weld by the combination of axial stresses due to axial forces, fit-up stresses, and weld residual stresses, could give rise to significant flaw-tip plasticity, which might render the LEFM results to be non-conservative. The objective of the present study was to employ Elastic Plastic Fracture Mechanics (EPFM) to determine CFS values, and then compare these values to CFS values evaluated using LEFM. CFS values were calculated for twelve cases involving surface and embedded flaws, EPFM analyses with and without plastic shakedown of the stresses, LEFM analyses, and various welding residual stress distributions. For the cases examined, the computed CFS values based on elastic analyses were the smallest in all instances where the failures were predicted to be controlled by the fracture toughness. However, in certain cases, the CFS values predicted by the elastic-plastic analyses were smaller than those predicted by the elastic analyses; in these cases the failure criteria were determined by a breakdown in stress intensity factor validity limits for deep flaws (a greater than 0.90t), rather than by the fracture toughness. Plastic relaxation of stresses accompanying shakedown always increases the cal

Elastic Plastic Fracture Mechanics

Elastic Plastic Fracture Mechanics PDF
Author: Lars Hannes Larsson
Publisher: Springer Science & Business Media
ISBN: 9400953801
Size: 80.45 MB
Format: PDF, Docs
Category : Science
Languages : en
Pages : 536
View: 3922

Get Book

Proceedings of the 4th Advanced Seminar on Fracture Mechanics, Joint Research Centre, Ispra, Italy, October 24-28, 1983

J Integral Elastic Plastic Fracture Mechanics Evaluation Of The Stability Of Cracks In Nuclear Reactor Pressure Vessels

J integral Elastic Plastic Fracture Mechanics Evaluation of the Stability of Cracks in Nuclear Reactor Pressure Vessels PDF
Author:
Publisher:
ISBN:
Size: 33.73 MB
Format: PDF, ePub, Mobi
Category :
Languages : en
Pages :
View: 6755

Get Book

Contributions were made toward developing a new methodology to assess the stability of cracks in pressure vessels made from materials that exhibit a significant increase in toughness during the early increments of crack growth. It has a wide range of validity from linear elastic to fully plastic behavior.

Fracture Mechanics

Fracture Mechanics PDF
Author: Nestor Perez
Publisher: Springer
ISBN: 3319249991
Size: 10.39 MB
Format: PDF, ePub, Mobi
Category : Science
Languages : en
Pages : 418
View: 2863

Get Book

The second edition of this textbook includes a refined presentation of concepts in each chapter, additional examples; new problems and sections, such as conformal mapping and mechanical behavior of wood; while retaining all the features of the original book. The material included in this book is based upon the development of analytical and numerical procedures pertinent to particular fields of linear elastic fracture mechanics (LEFM) and plastic fracture mechanics (PFM), including mixed-mode-loading interaction. The mathematical approach undertaken herein is coupled with a brief review of several fracture theories available in cited references, along with many color images and figures. Dynamic fracture mechanics is included through the field of fatigue and Charpy impact testing.

Computational Methods In The Mechanics Of Fracture

Computational Methods in the Mechanics of Fracture PDF
Author: Satya N. Atluri
Publisher: Elsevier Science Limited
ISBN:
Size: 58.79 MB
Format: PDF, Kindle
Category : Technology & Engineering
Languages : en
Pages : 414
View: 5533

Get Book

This volume not only covers the fundamental concepts of fracture mechanics, but also the computational methodologies necessary for practical engineering designs aimed at fracture control. It gives a concise summary of various fracture theories: linear elastic, elastic-plastic, and dynamic fracture mechanics of metals and composites. Novel numerical methods (finite element and boundary element) that enable the treatment of complicated engineering problems are emphasized. Examined are problems of linear elastic fracture of metallic and non-metallic composite materials, three-dimensional problems of surface flaws, elastic-plastic fracture, stable crack growth, and dynamic crack propagation. A comprehensive outline of the energetic approach and energy integrals on fracture mechanics is also given. Contents: Preface. Parts: I. Chapters: 1. Fracture: Mechanics or Art? (F. Erdogan). II. 2. Linear Elastic Fracture Mechanics (A.S. Kobayashi). 3. Elastic-Plastic Fracture (Quasi-Static) (S.N. Atluri and A.S. Kobayashi). 4. Dynamic Crack Propagation in Solids (L.B. Freund). 5. Energetic Approaches and Path-Independent Integrals in Fracture Mechanics (S.N. Atluri). III. 6.

The Crack Tip Opening Displacement In Elastic Plastic Fracture Mechanics

The Crack Tip Opening Displacement in Elastic Plastic Fracture Mechanics PDF
Author: K.H. Schwalbe
Publisher: Springer Science & Business Media
ISBN: 3642828183
Size: 28.66 MB
Format: PDF, ePub, Docs
Category : Science
Languages : en
Pages : 360
View: 842

Get Book

Sponsored by Studiengesellschaft zur Förderung der Kern- energieverwertung im Schiffbau und Schiffahrt e.V. (KEST), Hamburg/Stiftung Volkswagenwerk, Hannover

Elastic Plastic Fracture

Elastic Plastic Fracture PDF
Author: C. F. Shih
Publisher: ASTM International
ISBN: 9780803107274
Size: 17.72 MB
Format: PDF, ePub, Docs
Category : Electronic book
Languages : en
Pages :
View: 6655

Get Book