Download or read book A Re Evaluation of Finite Element Models and Stress Intensity Factors for Surface Cracks Emanating from Stress Concentrations written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-28 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: A re-evaluation of the 3-D finite-element models and methods used to analyze surface crack at stress concentrations is presented. Previous finite-element models used by Raju and Newman for surface and corner cracks at holes were shown to have ill-shaped elements at the intersection of the hole and crack boundaries. These ill-shaped elements tended to make the model too stiff and, hence, gave lower stress-intensity factors near the hole-crack intersection than models without these elements. Improved models, without these ill-shaped elements, were developed for a surface crack at a circular hole and at a semi-circular edge notch. Stress-intensity factors were calculated by both the nodal-force and virtual-crack-closure methods. Both methods and different models gave essentially the same results. Comparisons made between the previously developed stress-intensity factor equations and the results from the improved models agreed well except for configurations with large notch-radii-to-plate-thickness ratios. Stress-intensity factors for a semi-elliptical surface crack located at the center of a semi-circular edge notch in a plate subjected to remote tensile loadings were calculated using the improved models. The ratio of crack depth to crack length ranged form 0.4 to 2; the ratio of crack depth to plate thickness ranged from 0.2 to 0.8; and the ratio of notch radius to the plate thickness ranged from 1 to 3. The models had about 15,000 degrees-of-freedom. Stress-intensity factors were calculated by using the nodal-force method. Tan, P. W. and Raju, I. S. and Shivakumar, K. N. and Newman, J. C., Jr. Langley Research Center RTOP 505-63-01-05...
Download or read book A Re evaluation of Finite element Models and Stress intensity Factors for Surface Cracks Emanating from Stress Concentrations written by and published by . This book was released on 1988 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Finite Element Models and Stress Intensity Factors for Surface Cracks Emanating from Stress Concentrations written by JC. Newman and published by . This book was released on 1990 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper presents an evaluation of the three-dimensional finite-element models and methods used to analyze surface cracks at stress concentrations. Previous finite-element models used by Raju and Newman for surface and corner cracks at holes were shown to have "ill-shaped" elements at the intersection of the hole and crack boundaries. These ill-shaped elements tended to make the model too stiff and, hence, gave lower stress-intensity factors near the hole-crack intersection than models without these elements. Improved models, without these ill-shaped elements, were developed for a surface crack at a circular hole and at a semicircular edge notch. Stress-intensity factors were calculated by both the nodal-force and virtual-crack-closure methods. Both methods and different models gave essentially the same results. Comparisons made between the previously developed stress-intensity factor equations and the results from the improved models agreed well except for configurations with large notch-radii-to-plate-thickness ratios.
Download or read book Stress intensity Factor Equations for Cracks in Three dimensional Finite Bodies Subjected to Tension and Bending Loads written by J. C. Newman and published by . This book was released on 1984 with total page 98 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 1989 with total page 984 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Improved Stress intensity Factors for Semi elliptical Surface Cracks in Finite thickness Plates written by I. S. Raju and published by . This book was released on 1977 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Review and Assessment of the Stress intensity Factors for Surface Cracks written by J. C. Newman (Jr) and published by . This book was released on 1978 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Weight Function Methods in Fracture Mechanics written by Xue-Ren Wu and published by Springer Nature. This book was released on 2022-07-04 with total page 665 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a systematic and standardized approach based on the authors’ over 30 years of research experience with weight function methods, as well as the relevant literature. Fracture mechanics has become an indispensable tool for the design and safe operation of damage-tolerant structures in many important technical areas. The stress intensity factor—the characterizing parameter of the crack tip field—is the foundation of fracture mechanics analysis. The weight function method is a powerful technique for determining stress intensity factors and crack opening displacements for complex load conditions, with remarkable computational efficiency and high accuracy. The book presents the theoretical background of the weight function methods, together with a wealth of analytical weight functions and stress intensity factors for two- and three-dimensional crack geometries; many of these have been incorporated into national, international standards and industrial codes of practice. The accuracy of the results is rigorously verified, and various sample applications are provided. Accordingly, the book offers an ideal reference source for graduate students, researchers, and engineers whose work involves fracture and fatigue of materials and structures, who need not only stress intensity factors themselves but also efficient and reliable tools for obtaining them.
Download or read book Stress intensity Factor Equations for Cracks in Three dimensional Finite Bodies written by and published by . This book was released on 1981 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Stress Intensity Factors Using General Finite Element Models written by IS. Raju and published by . This book was released on 1999 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: Finite-element methods are commonly used to evaluate cracked solids. Post-processing methods are used to extract Mode I stress-intensity factor values from finite-element analyses. These methods include the Crack-Opening-Displacement (COD) method, the Force method, the Virtual Crack Closure Technique (VCCT) and the Equivalent Domain Integral (EDI) method. The COD method, Force method and the VCCT appear to require that the finite-element mesh intersect the crack front in an orthogonal manner in order to obtain accurate stress-intensity factor values. The EDI does not appear to require this orthogonality with the crack front to obtain accurate stress intensity factor values. The objectives of this study are to determine if accurate stress intensity factor values can be obtained from finite-element models that lack orthogonality with the crack front and, if accurate values cannot be obtained, to modify the extraction methods so that accurate stress-intensity factor values can be obtained from models without orthogonality at the crack front.
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1995 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of Surface Cracks at Hole by a 3 D Weight Function Method with Stresses from Finite Element Method written by and published by . This book was released on 1995 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1973 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on with total page 1224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Stress intensity Factors for Cracked Solids Using General Finite element Models written by Steven Arnold Smith and published by . This book was released on 1997 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government reports annual index written by and published by . This book was released on 199? with total page 1362 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fracture Mechanics written by J. C. Lewis and published by ASTM International. This book was released on 1983 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt:
