Download or read book An Evaluation of Crack Growth from Loaded Fastener Holes Treated with Cold expansion written by John Regis Minotti and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This work assesses the effects of residual stress, introduced via cold hole expansion (CX), on fatigue crack growth through clad 7075-T6 and 7075-T651 aluminum. This was done by comparing fatigue crack growth through samples without residual stress treatments (AM) to the crack growth through CX samples. Loaded hole and nested angle coupons were tested, representing an idealized loaded hole connection, and an actual splice joint used in rotorcraft assemblies, respectively. The effects of load interaction was evaluated through all sample configurations by comparing fatigue crack growth under constant amplitude sinusoidal loading and a variable amplitude load program. All loaded hole test data was compared to linear elastic fracture mechanics (LEFM) predictions of crack growth, which used superposition to combine the effects of applied and residual stress and the Modified Generalized Willenborg Model of crack closure. Nested angle crack growth was catalogued to support future lifing of nested angle samples and future development of crack growth models. Overall the LEFM approach provided good predictions of crack growth through AM and select CX loaded hole coupons under both load profiles. These results demonstrate the ability of LEFM with superposition to predict CX crack growth through loaded hole samples under constant amplitude and spectrum loading. Nested angle testing shows that current nested angle CX treatments do not affect fatigue performance, which is dominated by the influences of friction, contact and bending. Offered are techniques to quantify two-dimensional crack growth by photogrammetrically quantifying marker bands. Also addressed are test procedures necessary to achieve the desired one and two-dimensional crack growth in all samples, and to avoiding fretting failure.

Download or read book Extended Study of Flaw Growth at Fastener Holes written by T. M. Hsu and published by . This book was released on 1978 with total page 347 pages. Available in PDF, EPUB and Kindle. Book excerpt: An analytical and experimental investigation was conducted to characterize the fracture and cyclic-growth behavior of cracks emanating from various types of fastener holes, such as open, close-tolerance, interference- fit, and cold-worked fastener holes. An analytical approach was developed for estimating stress intensity factors for through cracks emanating from these types of fastener holes. Approximate stress intensity factors for quarter- elliptical cracks emanating from a corner of the same types of fastener holes were derived from corresponding through-crack solutions. Two alloy plates (2219- T851 aluminum and 6Al-4V (ELI) beta annealed titanium) with and without intentional initial flaws were tested under constant amplitude cyclic load and flight-by-flight fighter and bomber spectrum loads. Two initial flaw shapes corresponding to a quarter-circular corner crack and a through-the-thickness crack and three initial crack lengths (small, intermediate and large) were used in the test program. Three levels of cold working and interference and one level of fastener load transfer were included for each alloy. The amount of load transferred through the loaded fastener was maintained uniformly at the level which produced a bearing stress equal to the far-field stress. Correlations between calculated stress intensities and those reduced from fatigue crack growth data were good, except for very small cracks growing from the cold-worked holes. Also, the natural cracks initiated in the fatigue tests were most commonly corner and embedded types whose shapes corresponded quite closely to the quarter- and semi-elliptical shapes used in the analyses.

Download or read book Extended Study of Flaw Growth at Fastener Holes Volume 2 Data Tabulations written by T. M. Hsu and published by . This book was released on 1978 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: An analytical and experimental investigation was conducted to characterize the fracture and cyclic-growth behavior of cracks emanating from various types of fastener holes, such as open, close-tolerance, interference- fit, and cold worked fastener holes. An analytical approach was developed for estimating stress intensity factors for through cracks emanating from these types of fastener holes. Approximate stress intensity factors for quarter- elliptical cracks emanating from a corner or the same types of fastener holes were derived from corresponding through-crack solutions. Two alloy plates (2219- T851 aluminum and 6Al-4V(ELI) beta annealed titanium) with and without intentional initial flaws were tested under constant amplitude cyclic load and flight-by-flight fighter and bomber spectrum loads. Two initial flaw shapes corresponding to a quarter-circular corner crack and a through-the-thickness crack and three inital crack lengths (small, intermediate and large) were used in the test program. Three levels of cold working and interference and one level of fastener load transfer were included for each alloy. The amount of load transferred through the loaded fastener was maintained uniformly at the level which produced a bearing stress equal to the far-field stress.

Download or read book An Experimental Study of Fatigue Crack Growth from Fastener Holes Repaired by Coldworking written by Walter Joseph Cesarz and published by . This book was released on 1978 with total page 184 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 1975 with total page 978 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fatigue Crack Growth Under Residual Stresses Around Holes written by Ramesh Nagaralu and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Compressive residual stresses induced by tensile overloads, compressive under loads, or by a cold-expansion process in specimens containing a circular hole and their influence on subsequent fatigue crack growth in aluminum alloys are studied. The finite element method is used to calculate residual stresses. The superposition method, which uses crack-tip stress intensity factors for cases involving remote loading and residual stresses, is used to calculate crack growth life for three kinds of tests from the literature: (1) fatigue of a circular hole specimen after an overload or under load, (2) single crack growing from a circular hole after a severe tensile overload, and (3) single crack growing from a circular hole after cold-working, reaming and notching. All specimens were subjected to subsequent constant amplitude loading. The superposition method worked fairly well for most cases, but tended to over predict fatigue life for small cracks and for cracks growing under residual stresses, which produce compressive (maximum and minimum) stress intensity factors.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1984 with total page 1294 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fatigue Crack Growth Under Residual Stresses Around Holes written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Compressive residual stresses induced by tensile overloads, compressive under loads, or by a cold-expansion process in specimens containing a circular hole and their influence on subsequent fatigue crack growth in aluminum alloys are studied. The finite element method is used to calculate residual stresses. The superposition method, which uses crack-tip stress intensity factors for cases involving remote loading and residual stresses, is used to calculate crack growth life for three kinds of tests from the literature: (1) fatigue of a circular hole specimen after an overload or under load, (2) single crack growing from a circular hole after a severe tensile overload, and (3) single crack growing from a circular hole after cold-working, reaming and notching. All specimens were subjected to subsequent constant amplitude loading. The superposition method worked fairly well for most cases, but tended to over predict fatigue life for small cracks and for cracks growing under residual stresses, which produce compressive (maximum and minimum) stress intensity factors.

Download or read book ICAF 2011 Structural Integrity Influence of Efficiency and Green Imperatives written by Jerzy Komorowski and published by Springer Science & Business Media. This book was released on 2011-05-06 with total page 950 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the 26th Symposium of the International Committee on Aeronautical Fatigue are a widely referenced summary of advances in aeronautical design against fatigue. This is a bi-annual event and the proceedings have been published in book form for over 35 years.

Download or read book Stress Intensity Factors for Surface and Corner Cracked Fastener Holes by the Weight Function Method written by W. Zhao and published by . This book was released on 1995 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: The paper presents stress intensity factor solutions for surface and corner-cracked fastener holes by using an efficient and accurate three-dimensional weight function method. The approach is briefly described. Stress intensity factors for crack-face pressure loads of the type (x/r)n are provided, where n varies from 0 to 4. The geometry parameters considered are as follows: the ratio of the hole radius to plate thickness r/T = 1.5 (T = t for corner cracks, T = 2t for surface cracks); the crack aspect ratio a/c = 0.5, 1, and 1.5; the ratio of crack depth-to-plate thickness a/t = 0.1, 0.3, and 0.5. Based on the given solutions and the superposition principle, stress intensity factors for other load cases may be easily obtained. Examples are given for remote tension, biaxial tension, wedge loading in the hole, and simulated pin loading. Also, the effect of the residual stress field following cold expansion is considered for the remote tension loading condition.

Download or read book Fracture and Fatigue Crack Growth Behavior of Surface Flaws and Flaws Originating at Fastener Holes Volume I Results and Discussion written by L. R. Hall and published by . This book was released on 1974 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt: The combined experimental and analytical study was undertaken to investigate the fatigue crack growth behavior of surface flaws and part-thru and thru cracks originating at fastener holes. Three alloys (2219-T851 aluminum, 9Ni-4Co-0.2C steel, and 6Al-4V (ELI) beta annealed titanium) were tested under three different loading profiles (constant cyclic load, periodic overload, spectrum load). Surface flaw test variables included loading conditions (uniform tension, pure bending, combined bending and tension), stress ratio (0.1, 0.3, 0.5), initial flaw shape (0.15

Download or read book Aeronautical Engineering written by and published by . This book was released on 1991 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book British National Bibliography for Report Literature written by and published by . This book was released on 2001 with total page 116 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 1948 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fatigue Life Enhancement from Cold Expansion on Cracked Fastener Holes written by S. Thibault and published by . This book was released on 2004 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aeronautical Engineering A Cumulative Index to a Continuing Bibliography written by and published by . This book was released on 1988 with total page 516 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 1386 pages. Available in PDF, EPUB and Kindle. Book excerpt: