Showing papers in "Engineering Fracture Mechanics in 1981"

TL;DR: In this article, an empirical stress-intensity factor equation for a surface crack as a function of parametric angle, crack depth, crack length, plate thickness and plate width for tension and bending loads was presented.

TL;DR: In this paper, a good correlation was obtained for ΔK eff / ΔK = 0.33 R + 0.12 R 2 for high crack rates (> 1 μm/c.

TL;DR: In this article, the maximum normal-strain theory for fracture is modified as a new approach to the study of the angled crack problem, and the authors present predictions on the direction of initial crack extension and the fracture strength for plates containing a slit crack as well as those with an elliptic crack under uniform edge stresses.

TL;DR: In this paper, the influence of a circumferential crack on the torsional dynamic behavior of a shaft is studied, and the results show that the change in dynamic response due to the crack is high enough to allow detection of the crack and estimation of its location or magnitude.

TL;DR: In this article, the effects of the stress ratio and the grain size on the fatigue crack growth near the threshold in a low carbon steel were analyzed based on the crackclosure measurement and the microscopic observations of cracktip slip deformation and the fracture surface.

TL;DR: In this article, the effects of crack closure on fatigue crack growth rate in 7050 Al were studied with the aid of small-foil strain gages glued at positions near to the crack plane.

TL;DR: In this article, a modified cavity growth model is used to describe the variations observed at crack initiation, based on the results obtained on axisymmetric notched specimens which were used to evaluate the critical cavity growth at rupture, and a statistical approach incorporating the distribution of inclusions located in the vicinity of a crack tip is proposed.

TL;DR: In this article, the authors describe some simpler approximate methods which are both quick and cheap for estimating the stress intensity factor at the tip of a crack, which is a prerequisite for any fracture mechanics analysis of a cracked structure.

TL;DR: In this article, the application of the fracture mechanics approach to time-dependent high temperature crack growth has been reviewed and the utility of this approach to predict creep crack growth rate was examined.

TL;DR: In this article, the principle of the conservation of energy is used to derive a solution for the velocity of crack growth in viscoelastic materials, which generalizes earlier work by the same method that yielded only asymptotic solutions for crack velocity.

TL;DR: In this article, a D6 tool steel and a 1015 mild steel using two different load ratios, R = 0.2 and 0.4, respectively, were compared and it was concluded that the observed R dependence can be explained by the combination of the contribution of two different models: the new plastic yielding as well as the crack tip fracture processes.

TL;DR: In this paper, the initiation, propagation and closure behavior of microcracks were investigated through successive observations of fatigue process on the plain specimen surface in rotating bending tests of a mild steel, an α-brass and Al-alloys.

TL;DR: In this article, an analysis is made of shear lip width measurements and the transition from tensile mode fatigue cracks to shear-mode fatigue cracks, as observed on fatigue crack surfaces of aluminium alloy sheet material.

TL;DR: In this paper, the effect of the thickness, width, aspect ratio and geometry of the fracture toughness specimen on the resultant displacement due to growth of plastic zone and crack was evaluated and a new procedure for the determination of K IC has been proposed.

TL;DR: A review of literature dealing with the stress strain and limiting equilibrium of a cracked solid subjected to outer loading is given in this article, where the results of studying the unbounded solids of complicated configuration weakened by singular cracks and systems of cracks are presented.

TL;DR: In this article, the authors determined the fracture toughness of high strength aluminum alloys, determined with chevron-notched short bar and short rod specimens, in agreement with results from compact specimens only for K Ic MNm −3 2.

TL;DR: In this paper, a new method for the measurement of displacement field around cracks by using the so-called white light speckles was developed by spraying the specimen surface with a layer of white paint and then adding another layer of black paint, and the resulting specklegram is then optical Fourier transformed to yield displacement information in terms of Young's fringes, or isothetics.

TL;DR: In this paper, the incipient fracture angle and fracture locus of prenotched brittle-like material subjected to compressive loading are investigated analytically and experimentally, and the analysis of the problem includes parameters whose effects on fracture were pronounced via laboratory tests, namely: notch-tip curvature, subcritical microcracks emanating from the notch and crack closure process.

TL;DR: In this article, a displacements and resultant forces model for a finite internally cracked plate is proposed, which satisfies: (a) the equilibrium and compatibility condition in the region occupied by cracked plate; (b) stress free condition on the surface of crack; (c) single value condition of displacements around the crack.

TL;DR: In this article, an analysis for the in-plane biaxial loading of an elastic system consisting of a partially bonded rigid elliptic inclusion embedded in an infinite matrix where the bond imperfections are two symmetric cracks is presented.

TL;DR: In this paper, approximate solutions have been presented for the crack tip stress intensity factor in a radially cracked autofrettaged or thermally stressed thick cylinder, with or without internal pressure.

TL;DR: In this paper, fracture toughness tests in shear modes (modes II and III) have been performed on short glass fiber composites through the use of special fixtures designed for the purpose.

TL;DR: In this paper, it was shown that the stress intensity factors for the end rotation problem for a cracked-rectangular sheet can be determined from a knowledge of the solution for a uniform normal displacement without rotation.

TL;DR: In this article, the maximum stress criterion for brittle fracture is examined and modified so that it may be applied to both the slit model and the elliptic model for a crack, and then applied this criterion to a study of the angled crack problem for plates with a slit crack as well as those with an elliptic crack.

TL;DR: In this paper, a new multiaxial distribution function with location parameters was proposed, involving both effects of internal and surface cracks, and some discussions were performed about fracture probability ratios and expected values of fracture stresses.

TL;DR: In this paper, several formulations of moving-singularity finite element procedures for fast fracture analysis are evaluated as to their accuracy and efficiency, and several of them are shown to have good performance.

TL;DR: In this paper, it was shown that nonlinear effects, even at small loads, lead either to crack-opening or apparent interpenetration of the crack-faces when the loading is of Mode II-type.

TL;DR: The core region defined by the method of caustics has been shown to be the limiting boundary of the non-linear elastic (or plastic) zone surrounding the crack tip.