Download or read book Three Dimensional Elastic Plastic Analysis of Shallow Cracks in Single Edge Crack Tension Specimens written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-13 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three dimensional, elastic-plastic, finite element results are presented for single-edge crack-tension specimens with several shallow crack-length-to-width ratios (0.05 less than or equal to a/W less than or equal to 0.5). Results showed the need to model the initial yield plateau in the stress-strain behavior to accurately model deformation of the A36 steel specimens. The crack-tip-opening-displacement was found to be linearly proportional to the crack-mouth-opening displacement. A new deformation dependent plastic-eta factor equation is presented for calculating the J-integral from test load-displacement records. This equation was shown to be accurate for all crack lengths considered. Shivakumar, Kunigal N. and Newman, James C., Jr. Langley Research Center RTOP 505-63-01-05...

Download or read book Three dimensional Elastic plastic Analysis of Shallow Cracks in Single edge crack tension Specimens written by and published by . This book was released on 1990 with total page 36 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 1995 with total page 542 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Three Dimensional Elastic Plastic Finite Element Analyses of Constraint Variations in Cracked Bodies written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-10-24 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three-dimensional elastic-plastic (small-strain) finite-element analyses were used to study the stresses, deformations, and constraint variations around a straight-through crack in finite-thickness plates for an elastic-perfectly plastic material under monotonic and cyclic loading. Middle-crack tension specimens were analyzed for thicknesses ranging from 1.25 to 20 mm with various crack lengths. Three local constraint parameters, related to the normal, tangential, and hydrostatic stresses, showed similar variations along the crack front for a given thickness and applied stress level. Numerical analyses indicated that cyclic stress history and crack growth reduced the local constraint parameters in the interior of a plate, especially at high applied stress levels. A global constraint factor alpha(sub g) was defined to simulate three-dimensional effects in two-dimensional crack analyses. The global constraint factor was calculated as an average through-the-thickness value over the crack-front plastic region. Values of alpha(sub g) were found to be nearly independent of crack length and were related to the stress-intensity factor for a given thickness. Newman, J. C., Jr. and Bigelow, C. A. and Shivakumar, K. N. Langley Research Center RTOP 505-63-50-04

Download or read book Numerical Assessments of Cracks in Elastic Plastic Materials written by Huang Yuan and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book a systematic discussion of crack problems in elastic-plastic materials is presented. The state of the art in fracture mechanics research and assessment of cracks is documented, with the help of analytic, asymptotic methods as well as finite element computations. After a brief introduction to fracture mechanics, the two-parameter concept for stationary cracks is studied in addition to the issues in three-dimensional crack fields under coupling with strong out-of-plane effects. Cracks along interfaces and crack growth problems under mixed mode conditions are also treated. A systematic study of stress singularities for different notches is accompanied by detailed finite element computations.

Download or read book Numerical Methods in Fracture Mechanics written by Anthony Roger Luxmoore and published by . This book was released on 1990 with total page 696 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 1979 with total page 988 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Integrity of Pipelines Transporting Hydrocarbons written by Gabriella Bolzon and published by Springer. This book was released on 2011-05-10 with total page 331 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes technical and practical aspects of pipeline damage. It summarizes the phenomena, mechanisms and management of pipeline corrosion in-service. The topics discussed include pipelines fracture mechanics, damage mechanisms and evolution, and pipeline integrity assessment. The concept of acceptable risk is also elucidated and the future application of new knowledge management tools is considered.

Download or read book Fatigue and Fracture Mechanics written by Robert S. Piascik and published by ASTM International. This book was released on 1997 with total page 640 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Shallow Crack Fracture Mechanics Toughness Tests and Applications written by Gyoujin Cho and published by Elsevier. This book was released on 1992-01-01 with total page 309 pages. Available in PDF, EPUB and Kindle. Book excerpt: Within the last decade there has been an increasing awareness that use of standards deeply notched fracture mechanics test specimens can result in substantial over-or-under-assessments of the real fracture toughness associated with shallow surface cracks.

Download or read book Numerical Methods in Fracture Mechanics written by and published by . This book was released on 1990 with total page 698 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Limits of J T Characterization of Elastic Plastic Crack Tip Fields written by DM. Parks and published by . This book was released on 1995 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plane strain elastic-plastic analyses were performed on a variety of 2-D planar cracked geometries and loading conditions, based on a small strain formulation and de-formation theory plasticity (termed finite boundary (FB) analysis hereafter). For the majority of the cases analyzed, the crack-tip fields in the mechanistically significant region around the crack tip agreed well with those of the corresponding modified boundary layer (MBL) solutions for load levels up to large scale yielding. The crack-tip fields in the MBL solutions were normalized using the elastic-plastic J values and the elastically-scaled T-stress values of the corresponding FB specimens. However, good agreement could be obtained with (J, T) only up to moderate scale yielding for a center-cracked tension (CCT) geometry. At large scale yielding, the MBL solution based on the elastically-scaled T-stress could not capture the effects of crack tip stress and strain redistribution in the CCT. An alternative method was proposed to calculate the T-stress using weight functions and the elastic-plastic remote stress field of the CCT (termed effective T-stress). Incorporating the effective T-stress into the MBL solutions, good agreement in both stress and strain fields was obtained between the MBL solution and the FB CCT solution at load levels up to general yielding. To demonstrate the limits of two-parameter characterizations in accurately describing elastic-plastic cracktip fields, a three-point-bend specimen was analyzed for load levels up to large plasticity. It is shown that although Q-values could be operationally defined at large plasticity, in general, no complete, consistent, two-parameter description was forthcoming to accurately describe the crack-tip stress and strain fields beyond certain limits. The inherent limits of two-parameter characterization of elastic-plastic crack tip fields should be recognized, analogous to those of one-parameter (J) characterization. A locus of two-parameter (J, T) characterization limits is proposed based on the crack-tip stress fields of the geometry and loading configurations analyzed. The J-T based two-parameter approach is shown to greatly extend the validity domain of fracture mechanics analysis for specimens with negative T-stress.

Download or read book Surface crack Growth written by Walter G. Reuter and published by ASTM International. This book was released on 1990 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the symposium (on title) held in Sparks, Nevada, April 1988. Twenty-two peer-reviewed papers are divided into sections on models and experiments (monotonic loading), and fatigue crack growth. Areas addressed include the differences in constraint for 2-D through-thickness cracks and 3-D surface

Download or read book Government Reports Annual Index written by and published by . This book was released on 1990 with total page 1316 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book On the Variation in Crack Opening Stresses at Different Locations in a Three Dimensional Body written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-09 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: Crack propagation and closure behavior of thin, and thick middle crack tension specimens under constant amplitude loading were investigated using a three dimensional elastic plastic finite element analysis of fatigue crack propagation and closure. In the thin specimens the crack front closed first on the exterior (free) surface and closed last in the interior during the unloading portion of cyclic loading; a load reduced displacement technique was used to determine crack opening stresses at specified locations in the plate from the displacements calculated after the seven cycle. All the locations were on the plate external surface and were located near the crack tip, behind the crack tip, at the centerline of the crack. With this technique, the opening stresses at the specified points were found to be 0.52, 0.42, and 0.39 times the maximum applied stress. Chermahini, R. G. and Blom, Anders F. Unspecified Center NAG1-529...

Download or read book Applied mechanics reviews written by and published by . This book was released on 1948 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Stress Analysis of Cracks Handbook written by Hiroshi Tada and published by Wiley. This book was released on 2000-07-26 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In a convenient hardcover format this extensive source of crack stress analysis has been brought up-to-date with the addition of 150 new pages of analysis and information. The book is an excellent reference, as well as a text for in-house training courses, in various industrial and academic settings. CONTENTS INCLUDE: Introductory Information: Crack-tip stress fields for linear-elastics bodies Alternate expressions for crack-tip elastic fields Energy rate analysis of crack extension Stress analysis results for common test specimen configurations: The center cracked test specimen The single edge notch test specimen Other common specimen configurations Two-dimensional stress solutions for various configurations with cracks: A finite crack in an infinite plane A periodic array of cracks in an infinite plane Opposing parallel semi-infinite cracks in an infinite plane A semi-infinite crack parallel to edges of an infinite strip Three-dimensional cracked configurations: An embedded circular crack in an infinite body A half-circular surface crack in a semi-infinite body Strip yield model solutions: Three-dimensional strip yielding solutions A circumferential crack in a cylindrical shell A crack in a spherical shell.