Showing papers in "Engineering Fracture Mechanics in 2004"

TL;DR: The main similarities and differences between normal engineering materials and bone tissue from a structural point of view are demonstrated to demonstrate the importance of computational simulations in biomechanics due to the difficulty of obtaining experimental or clinical results.

TL;DR: In this paper, the effects of stress triaxiality and initial porosity on void growth and coalescence were studied and the results showed that the effect of the traciaxiality on the void growth rate and the macroscopic stress-strain response was independent of the porosity of the void.

TL;DR: The state-of-the-art in finite element analysis for plasticity-induced fatigue crack closure can be found in this article, where a comprehensive overview is presented, summarizing issues which must be considered and emphasizing potential difficulties.

TL;DR: In this article, a study was conducted to examine the recently proposed fatigue crack driving force parameter, K ∗ =K max α ( Δ K + ) (1−α), and its ability to predict the crack growth rate for different R-ratios.

TL;DR: In this paper, a two-parameter model for the fracture of cementitious materials is modelled with a back-propagation ANN and the results of the ANN-based model look viable and very promising.

TL;DR: A new statistical local criterion for Cleavage is proposed, which expresses the necessity of maintaining a critical dynamic connectivity between microcrack nucleation and unstable propagation in order for cleavage fracture to occur.

TL;DR: In this article, the authors describe a critical distance theory which uses local stress field information to predict the effect of stress concentrations on fracture strength in ceramics containing notches, long cracks and short cracks.

TL;DR: In this paper, the size effect on structural strength is discussed in most specifications of the design codes for concrete structures, as well as the design practices for polymer composites, rock masses and timber.

TL;DR: In this article, the authors presented a plane solution for the stresses and electric fields in an infinite body around a cylindrical cavity with an elliptical cross-section, where the electric field from the interior of the cavity was used in conjunction with the energy change formula to calculate the total energy release rate per crack tip when a Griffith crack propagates.

TL;DR: In this article, a beam model of end notched flexure (ENF) specimen for mode-II fracture testing is presented, where the beam deformation is modeled as two subproblems: (1) an uncracked beam under three-point bending; and (2) a skew symmetric cracked beam under shear traction on the crack surface.

TL;DR: In this article, the series expressions of σθ, τrθ and σr in the uncracked circular disk under diametral compression loading are given, and general expressions of the coefficients Aji corresponding to the stress components are derived.

TL;DR: In this article, a crack in an infinite solid subjected to linear loading normal to the crack surface is considered accounting for free water viscosity and inertia effect, and results are obtained for the relationship between the dynamic fracture initiation toughness and the fracture initiation time.

TL;DR: In this article, a mesh-free Lagrangian method called smooth particle hydrodynamics (SPH) is used in numerical simulation to simulate the fragmentation of concrete due to explosive loading.

TL;DR: In this article, a non-equilibrium formulation for evaluating T -stress in functionally graded materials with mixed-mode cracks is developed, where the gradation of material properties is integrated into the element stiffness matrix using the so-called generalized isoparametric formulation.

TL;DR: A combined finite-discrete element model for failure and collapse of structural systems comprising of reinforced concrete beam or column type structural members has been developed and implemented into a combined finite discrete element code as mentioned in this paper.

TL;DR: In this article, fatigue crack growth tests were conducted on double cantilever beam bonded specimens with the aim of characterizing an adhesive for structural applications, and the role of loading frequency was also addressed.

TL;DR: In this article, a finite element algorithm that combines a Maxwell creep model, with a 3-D continuum damage mechanics approach modeling anisotropic damage accumulation is used to predict the locations of cement damage around the implants and the amount of implant migration attributable to creep.

TL;DR: In this article, a series of notched cylindrical specimens, peened by using different parameters, was fatigue tested, being the aim to determine the improvement of the fatigue limit of the treated specimens.

TL;DR: In this paper, a 3D finite element (FE) analysis was performed on standard and non-standard fracture toughness testing specimens, and the results showed that the use of the CMOD overall provides more robust experimental J estimation than that of the LLD.

TL;DR: In this article, the Weibull modulus, m, increases with temperature to reflect the increasing microscale toughness of ferritic steels caused by local events that include plastic shielding of microcracks, microcrack blunting, and micro-crack arrest, and a more practical approach developed here utilizes the so-called Master Curve standardized in ASTM Test Method E1921-02 to provide the needed temperature vs toughness dependence for a material using a minimum number of fracture tests conducted at one temperature.

TL;DR: In this paper, a cohesive zone model is proposed for modeling interface fracture near flaws in adhesive joints, and the results from simulations of fracture in a bond containing circular flaws show that localization of crack propagation in the vicinity of a flaw has significant effect on the joint strength and crack front shape.

TL;DR: In this article, the applicability of standard composite mode I interlaminar toughness data reduction schemes for composites reinforced by inserting straight pins in the z-direction is investigated, and a simple model of a z-pinned mode I test is used to generate load, displacement and crack length data.

TL;DR: In this article, a new comparatively simple extension of the MC is introduced for inhomogeneities governed by two separate MC distributions, which is shown to be extremely efficient in describing eg weld heat-affected zone (HAZ) data.

TL;DR: In this paper, the authors studied the ductile tearing of laser welded Al sheets, both experimentally and numerically, using the Gurson-Tvergaard-Needleman model.

TL;DR: In this article, a new model for cleavage fracture in steel was presented, based on a new statistical local criterion, which expresses the necessity of simultaneously fulfilling the conditions for both cleavage microcrack nucleation and propagation.

TL;DR: In this article, the Gurson model adapted by Tvergaard is extended by fitting, based on numerical results proposed in the literature, the tuning parameters q1 and q2 in order to better capture the effects of the strain hardening and void shape evolution.

TL;DR: In this article, detailed results of 3D finite element (FE) and mixed mode analyses of different fracture specimens are presented and discussed, where 3D and mode coupling effects are found in strain energy release rate (SERR) results along crack fronts, in particular adjacent to corners, where a crack front intersects a free surface of a specimen.

TL;DR: In this article, an improved crackclosure model, FASTRAN, was used to calculate crack growth under aircraft spectrum loading, which is related to more accurate development of the plasticity-induced closure mechanism, especially for high stress ratio spectra, and to using improved crack-growth rate results in the near threshold regime.

TL;DR: In this paper, the first discrete hexagonal element method can be considered as one of discrete element methods (DEM), which are very often used in mechanics of granular media and substitute the methods for solving continuum problems.

TL;DR: In this paper, the authors examined the bending fatigue life of thin-rim spur gears of truck gearboxes and divided the gear service life into the initiation phase of the damage accumulation and the crack growth, respectively.