Download or read book Three dimensional Elastic plastic Finite Element Analysis of Fatigue Crack Growth and Closure written by Rahmatollah Ghadimi Chermahini and published by . This book was released on 1986 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Three dimensional Finite element Simulation of Fatigue crack Growth and Closure written by Stephen G. Cupschalk and published by . This book was released on 1987 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Finite Element Analysis of Plasticity Induced Fatigue Crack Closure in Three Dimensional Cracked Geometries written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Elastic-plastic finite element analyses were performed to predict the crack opening level profiles in semi-elliptical surface cracks. A script was written to use the commercial finite element code ANSYS to predict opening levels in cracked geometries. The functionality of the scripts was verified by comparing predicted opening levels in two and three-dimensional center-cracked geometries to experimental results. In addition, a parameter study was performed in which various aspects of the modeling routine were modified. This included a mesh refinement study as well as a study into the effect of a strain hardening material. The main focus of the current research, however, is to compare finite element predicted opening levels with published opening levels determined experimentally. Due to the complexities and long run-times involved with these models, no attempt was made at growing the cracks from initial length to final length. Instead, discrete crack lengths at which experimental opening levels were published were instead used. Also, no attempt was made to predict the crack aspect ratio evolution. The finite element predicted opening levels were in all cases significantly lower than those reported experimentally, however, similar trends in both crack opening level profile along the crack front, and opening level variations with crack growth were shown.

Download or read book Three dimensional Elastic plastic Finite Element Analysis of Fatique Crack Growth and Closure written by R. G. Chermahini and published by . This book was released on 1986 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Three dimensional Elastic plastic Finite element Analysis of Fatigue Crack Propagation written by R. G. Chermahini and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Elastic plastic Finite Element Analysis of Fatigue Crack Growth in Mode 1 and Mode 2 Conditions written by and published by . This book was released on 1978 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Finite Element Elastic Plastic Analysis of Cracks written by Satya N. Atluri and published by . This book was released on 1978 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a summary of research performed in the areas: (a) development of two-dimensional hybrid finite element procedures to calculate stress intensity factors corresponding to general r to the minus alpha stress singularities in isotropic as well as anistropic materials; (b) study of the convergence of the assumed displacement hybrid finite element procedure in fracture mechanics problems; (c) development of a three-dimensional hybrid finite element procedure to calculate the elastic combined mode stress-intensity factors K1, K2 and K3 that vary along an arbitrarily curved three-dimensional crack front; (d) hybrid finite element solutions of fundamental three-dimensional crack problems; (e) development of a two-dimensional finite element procedure for analyzing plane problems of fracture involving large-scale yielding conditions and under cyclic loading; (f) study of the J-integral as a ductile fracture initiation condition; (g) studies of finite deformation effects near the crack-tip; (h) analysis of stable crack growth under rising load and study of criteria for loss of stability of growth in ductile materials; and (i) elastic-plastic analysis of effects of crack closure on fatigue crack growth rates. (Author).

Download or read book TWO AND THREE DIMENSIONAL FINITE ELEMENT ANALYSIS OF PLASTICITY INDUCED FATIGUE CRACK CLOSURE A COMPREHENSIVE PARAMETRIC STUDY written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Finite element analyses are frequently used to model growing fatigue cracks and the associated plasticity-induced crack closure. Two-dimensional, elastic-perfectly plastic finite element analyses of middle-crack tension (M(T)), bend (SEB), and compact tension (C(T)) geometries were conducted to study fatigue crack closure and to calculate the crack opening values under plane-strain and plane-stress conditions. The loading was selected to give the same maximum stress intensity factor in both geometries, and thus similar initial forward plastic zone sizes. Mesh refinement studies were performed on all geometries with various element types. For the C(T) geometry, negligible crack opening loads under plane-strain conditions were observed. In contrast, for the M(T) specimen, the plane-strain crack opening stresses were found to be significantly larger. This difference was shown to be a consequence of in-plane constraint. Under plane-stress conditions, it was found that the in-plane constraint has negligible effect, such that the opening values are approximately the same for the C(T), SEB, and M(T) specimens. Next, the crack opening values of the C(T), SEB and M(T) specimens were compared under various stress levels and load ratios. The effect of a highly refined mesh on crack opening values was noted and significantly lower crack opening values than those reported in literature were found. A new methodology is presented to calculate crack opening values in planar geometries using the crack surface nodal force distribution under minimum loading as determined from finite element analyses. The calculated crack opening values are compared with values obtained using finite element analysis and more conventional crack opening assessment methodologies. It is shown that the new method is independent of loading increment, integration method (normal and reduced integration), and crack opening assessment location. The compared opening values were in good agreement with strip-yield.

Download or read book Three dimensional Elastic plastic Finite element Analyses of Constraint Variations in Cracked Bodies written by and published by . This book was released on 1993 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Finite Element Analysis of Plasticity induced Fatigue Crack Closure in Three dimensional Cracked Geometries written by Jeffrey David Skinner and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: [3] The finite element predicted opening levels were in all cases significantly lower than those reported experimentally, however, similar trends in both crack opening level profile along the crack front, and opening level variations with crack growth were shown.

Download or read book Analysis of Fatigue Crack Growth and Residual Stress written by Shakhrukh Ismonov and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The first part of this dissertation employs a three-dimensional elastic-plastic finite element model of straight-through crack growth to correlate four well-known methodologies characterizing fatigue crack closure. The compliance offset and the adjusted compliance ratio (ACR) are experimental methods, whereas the node displacement and the contact stress methods are numerical approaches. Evolutions of crack closure from all four methodologies are compared for a numerical model of a single edge-cracked tension specimen subjected to different levels of constant amplitude cyclic loading. In the second part, a detailed two dimensional stress analysis is conducted for a single pin-joint under plane stress conditions. This study investigates the influence of material nonlinearity, friction, and pre-existing residual stresses from cold-working process on the local radial and hoop stress levels around the pin-loaded hole. Next, the beneficial influence of cold working process is quantified by computing the Mode I stress intensity factors K[subscript I] for a single radial crack emanating from a side of a loaded hole. Two different loading configurations are considered: (a) an open hole in tension, (b) a pin-loaded hole. The stress intensity factors are computed using the J integral solutions and the weight functions specific to the crack configuration. The reductions in K[subscript I] values due to different levels of cold-working process are presented for a range of crack lengths. The final part of the research involves a numerical investigation of an on-line crack compliance technique that is used for experimental measurements of residual stress fields along the crack growth path. A finite rectangular sheet is considered with a single crack emanating from a side of a central hole. The residual stress field is introduced around the hole by cold-working simulation. As part of validation, the normalized residual stress intensity factors computed using the on-line crack compliance technique are compared with those from the J-integral approach for the case of elastic crack growth. The influence of crack tip plasticity on the performance of the on-line crack compliance technique is studied by comparing the solutions of the elastic and elastic-plastic crack growth models.

Download or read book Fatique and Fracture Mechanics written by Gary R. Halford and published by ASTM International. This book was released on 2000 with total page 551 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mechanics of Fatigue Crack Closure written by Wolf Elber and published by ASTM International. This book was released on 1988 with total page 671 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Three dimensional Finite element Simulation of Fatigue crack Growth and Closure written by Stephen G. Cupschalk and published by . This book was released on 1987 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of a Practical Methodology for Elastic Plastic and Fully Plastic Fatigue Crack Growth written by R. Craig McClung and published by . This book was released on 1999 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Three dimensional Finite Element Analysis of Cyclic Fatigue Crack Growth of Multiple Surface Flaws written by Corneliu Manu and published by . This book was released on 1980 with total page 500 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 Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-13 with total page 46 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...