Download or read book Variability in Fatigue Crack Growth Rate Testing written by S. J. Hudak and published by . This book was released on 1974 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Variability in Fatigue Crack Growth Rate Testing written by W. G. Clark and published by . This book was released on 1974 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fatigue Crack Growth Measurement and Data Analysis written by S. J Hudak and published by ASTM International. This book was released on 1981 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fatigue Crack Growth Measurement and Data Analysis written by S. J. Hudak and published by ASTM International. This book was released on 1981 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Probabilistic Fracture Mechanics and Fatigue Methods written by J. M. Bloom and published by ASTM International. This book was released on 1983 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization of the Variability in Fatigue Crack Propagation Data written by DF. Ostergaard and published by . This book was released on 1983 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: The variability in fatigue crack propagation is studied through the analysis of 68 sets of replica constant amplitude fatigue crack growth data. Each of the a versus N data sets are fit to the integral of a crack growth rate equation through a finite integral optimization routine. The routine determines the best fit crack growth parameters of the crack growth rate equation. Through characterization of the variability in the crack growth parameters and utilizing statistical theory, the variability in the a versus N data is predicted. The finite integral method of obtaining the crack growth parameters was shown to very accurately reproduce the a versus N data. The variability in the crack growth parameters showed a strong linear trend, and a regression analysis on the parameters provided information to accurately predict the variability in the fatigue crack propagation data.
Download or read book Variability in Constant Load Amplitude Fatigue Crack Growth Rates in Marine Environments written by S. J. Gill and published by . This book was released on 1985 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the results of an interlaboratory test program conducted to (1) assess the variability in corrosion fatigue crack growth rate data obtained while using a proposed Navy standard test method, (2) identify and resolve problems with the proposed standard test method and (3) provide verification of the proposed standard test method. Data were generated for an HY-80 steel by 15 laboratories using 10 mm (0.4 in.) thick 1-T wedge-opening-loaded specimens. the crack growth rate data was analyzed graphically and statistically and the interlaboratory variability was determined for each set of test conditions. Owing to the lack of replicate tests, it was not possible to assess intralaboratory variability. Originator-supplied keywords: Base metal, Corrosion fatigue, Crack propagation, Nickel chromium steels, Sea water corrosion.
Download or read book Statistical Design of Fatigue Crack Growth Test Programs written by GC. Salivar and published by . This book was released on 1988 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental design method for determining statistically significant differences in fatigue crack growth rate data due to the influence of various test conditions (factors) is presented. This method is based on a completely randomized factorial design and a three-way classification Analysis of Variance (ANOVA) procedure. Although the example presented is for fatigue crack growth rate testing, this method is generic to any materials test program where comparisons of properties or behavior are made. The procedure allows decisions regarding these comparisons to be based on statistical tests of significance.
Download or read book Effect of Measurement Precision and Data Processing Procedures on Variability in Fatigue Crack Growth Rate Data written by RP. Wei and published by . This book was released on 1979 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Variability in experimental data on fatigue crack growth kinetics reflects contributions not only from material property variations and environmental and other uncontrolled variables but also from measurement precision used in determining the primary data (that is, crack length versus elapsed cycles) and the subsequent data processing procedures in determining rates from the primary data. To assess the contributions of measurement precision and data processing procedures to variability, computer simulation of primary fatigue crack growth data was made for a number of measurement intervals and precisions. These simulated data were analyzed by several data processing procedures.
Download or read book Evaluation of Linear Elastic Fracture Mechanics Predictions of One and Two dimensional Fatigue Crack Growth at Cold expanded Holes written by Daniel Haines Stuart and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This work assesses the ability of linear elastic fracture mechanics (LEFM) with superposition to correlate the growth of one and two-dimensional fatigue cracks at cold-expanded open holes under constant amplitude loading. Care is taken in the work to accurately: control the test setup to ensure growth of a single crack, determine residual stress in the coupons, measure crack growth, determine the fatigue crack growth rate (FCGR), compute stress intensity factors, and correlate fatigue crack growth rate with stress intensity factor range [delta]K and stress ratio R. The work used long dog-bone coupons made from 2.03 mm and 4.83 mm thick 7075-T6 sheet having a gage section 38.1 mm wide, a centrally located 7.09 mm diameter hole, with through thickness notches for thin and corner notches for thick coupons. Quarter elliptical stress intensity factors are used for thick coupons while one-dimensional stress intensity factors are used for thin coupons. Residual stress due to cold expansion (CX) was measured using the contour method as a function of position on the crack plane and gave typical results. Measurements on multiple coupons showed "10% variability in residual stress. Crack growth behavior of multiple as-machined (AM) coupons (without CX) tested at R of 0.1 or 0.5 agreed with earlier results published in the literature for both one and two dimensional cracks. Crack growth behavior of multiple thin CX coupons tested at the same two applied stress ratios was consistent with predictions by linear superposition, with scatter in lifetime consistent with the observed 10% variability in residual stress. LEFM based on quarter elliptical models was found to be ineffective to predict crack growth in CX coupons because the quarter elliptical shape assumption is inaccurate. The work therefore demonstrates the ability of LEFM with superposition to accurately correlate the behavior of coupons with and without residual stresses for one-dimensional crack growth, and only for AM for two-dimensional crack growth.
Download or read book The Effect of Periodic Overloads on Flight by flight Fatigue Crack Growth Rates written by Margery A. Dean and published by . This book was released on 1983 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: The life prediction of aerospace structures subjected to service loading conditions can be complex and expensive. Fortunately, many flight-by- flight loadings can be analyzed as constant amplitude loading if the variability in crack growth rate is low. A test program was designed such that the stress intensity factor (Kmax) was held constant by uniformly reducing the load as the fatigue crack grew. With a constant Kmax, the crack growth rate remains constant throughout the life of the test. The baseline fatigue crack growth rate variability was established for the 7075-T6 center-cracked panels under a flight-by-flight load history. The effect of introducing overloads to the baseline flight history on the crack growth rate variability was reported. The results indicate that the delay region for the applied 114% overloads was predicted by Irwin's plastic zone model and was equal to 0.0382 inches which was equal to 225 flights. The delay behavior was consistent for the several overload conditions that were studied. When the occurrence of overload increased, the fatigue crack growth decreased. The standard error of estimate remained relatively constant, suggesting that a block approach to life prediction is feasible for flight-by-flight load history.
Download or read book Fatigue Crack Growth Rate Measurements in Aluminum Alloy Forgings written by RJ. Bucci and published by . This book was released on 1993 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: An investigation to determine the causes of increased variability in fatigue crack growth (FCG) rate measurement in aerospace aluminum forgings compared to that observed in aluminum flat rolled plate was conducted. Fatigue cracks were grown at constant applied ?K, consistent with ASTM Test Method for Measurements of Fatigue Crack Growth Rates (E 647-88a), through regions of rapidly changing grain-flow direction within thin 7075-T73 precision forgings and large closed-die 7050-T74 forgings. The local grain flow in each specimen was correlated subsequently with measured crack growth rates so that the contribution of grain-flow variability to the scatter in measured crack growth rates could be determined. These results were found to be comparable to FCG results from 7075-T7351 and 7050-T7451 plate, once residual stress biases were removed by means of closure measurement. Hence, it is concluded that the effects of microstructural features such as grain flow on FCG rate are minimal, and the inherent FCG resistances of aerospace aluminum forgings and plate are comparable. Consequently, the analytical fracture mechanics framework applicable to damage tolerance verification of plate product should extend equally to forging product forms. However, the results indicate that failure to account for residual stress effects in interpretation of forging test results can lead to erroneous conclusions about the material performance.
Download or read book 7075 T6 and 2024 T351 Aluminum Alloy Fatigue Crack Growth Rate Data written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-24 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experimental test procedures for the development of fatigue crack growth rate data has been standardized by the American Society for Testing and Materials. Over the past 30 years several gradual changes have been made to the standard without rigorous assessment of the affect these changes have on the precision or variability of the data generated. Therefore, the ASTM committee on fatigue crack growth has initiated an international round robin test program to assess the precision and variability of test results generated using the standard E647-00. Crack growth rate data presented in this report, in support of the ASTM roundrobin, shows excellent precision and repeatability. Forth, Scott C. and Wright, Christopher W. and Johnston, William M., Jr. Langley Research Center NASA/TM-2005-213907, L-19163
Download or read book Fatigue Testing and Analysis Under Variable Amplitude Loading Conditions written by Peter C. McKeighan and published by ASTM International. This book was released on 2005 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Extension of a Microstructure Based Fatigue Crack Growth Model for Predicting Fatigue Life Variability written by MP. Enright and published by . This book was released on 2004 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most of the existing crack growth models rely on empirical constants derived from curve fits of data at specific test conditions. Although statistical information can be obtained for many of these constants, multiple experimental tests typically must be performed to represent the wide range of the response. In this paper, an alternative approach is presented that links fatigue crack growth parameters to material and microstructural size parameters via a microstructure-based fatigue crack growth (FCG) model. In addition, variation of initial crack size due to microstructural variation is modeled in terms of a crack-size-based fatigue crack initiation model. Variations of microstructural parameters are described in terms of a probabilistic framework. The probabilistic, microstructure-based, FCG approach is illustrated for a Ni-based superalloy in which the influence of changes in the main descriptors of the individual microstructural parameters on initial crack size, crack growth rate, and fatigue life is shown. Stochastic model results are compared with existing experimental data to illustrate the feasibility of the approach for predicting da/dN variability due to microstructure variations.
Download or read book Small Fatigue Cracks written by K.S. Ravichandran and published by Elsevier. This book was released on 1999-09-30 with total page 511 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the fully peer-reviewed papers presented at the Third Engineering Foundation Conference on Small Fatigue Cracks, held under the chairmanship of K.S. Ravichandran and Y. Murakami during December 6-11, 1998, at the Turtle Bay Hilton, Oahu, Hawaii. This book presents a state-of-the-art description of the mechanics, mechanisms and applications of small fatigue cracks by most of the world's leading experts in this field. Topics ranging from the mechanisms of crack initiation, small crack behavior in metallic, intermetallic, ceramic and composite materials, experimental measurement, mechanistic and theoretical models, to the role of small cracks in fretting fatigue and the application of small crack results to the aging aircraft and high-cycle fatigue problems, are covered.
Download or read book Journal of Testing and Evaluation written by and published by . This book was released on 1987 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt:
