Showing papers in "Theoretical and Applied Fracture Mechanics in 2009"

TL;DR: In this paper, a large bulk of experimental data from static tests of sharp and blunt V-notches and from fatigue tests of welded joints are presented in an unified way by using the mean value of the Strain Energy Density (SED) over a given finite-size volume surrounding the highly stressed regions.

TL;DR: In this article, the authors evaluated the resistance of ultra-high strength concrete targets by high-velocity impact experiments and showed that adding a small amount of steel fibers significantly improved the impact resistance of the target plates.

TL;DR: In this article, an experimental investigation on the dynamic mechanical properties of reactive powder concrete (RPC) was conducted using the split-Hopkinson pressure bar (SHPB) and the results showed the obvious rate-dependent mechanical behavior exists for RPC.

TL;DR: In this paper, a new paradigm referred to as crack tip mechanics (CTM) is proposed to represent inhomogeneity by crack-like defects as the cause of damage initiation, which can be viewed as an energy sink or source.

TL;DR: In this paper, a finite element formulation for the numerical prediction of the mechanical behavior of rubber-like materials which are reinforced with single walled carbon nanotubes is presented. And the influence of the single-walled carbon-nanotube addition within the rubber is clearly illustrated and discussed.

TL;DR: By means of numerical simulation, the special phenomenon of zonal disintegration of surrounding rock mass around the diversion tunnels of Jinping II Hydropower Station is analyzed in this paper. But the present result is different from the one obtained by the traditional elasto-plastic theory.

TL;DR: In this article, a numerical analysis of crater blasting in steel fiber reinforced concrete (SFRC) is presented, where the effective stress and effective plastic strain curve are tabulated and used as input for the material Type10 (MAT_ELASTIC_PLASTic_HYDRO) available in LS-DYNA.

TL;DR: In this paper, the different energies involved in the energy balance were deduced from two complementary imaging techniques, i.e., infrared thermography and digital image correlation system, and three tests with various loading blocks were carried out and a comparison between deformation and dissipation energies was systematically performed.

TL;DR: In this paper, a multiscale field theory for modeling and simulation of multi-grain material systems is presented, where the interatomic forces are used to formulate the governing equations for the system.

TL;DR: In this article, the authors presented the optimal design of a small-scale MSV pressure hull with a ring-stiffened cylinder and two hemispherical ends subjected to hydrostatic pressure, using a powerful optimization procedure combined the extended interior penalty function method (EIPF) with the Davidon-Fenton-Powell (DFP) method.

TL;DR: In this paper, the authors propose to use open system test data to determine the physical parameters of the transitional functions defined by the mean values of length (free path), velocity, mass and energy.

TL;DR: In this article, the critical strain energy density of Huanglong limestone was measured over a wide range of loading rates from 8.97×10−4 MPam1/2 s−1 to 1.545×1.545 MPam 1/2 S−1.

TL;DR: In this article, a new technique of estimating multiple Weibull parameters is conducted, compared to commonly used regression probability estimator, which is based on linear regression method for estimating parameters of a Weibell distribution.

TL;DR: In this paper, the thermoplastic resin Poly-Ether-eather-ketone (PEEK) was used to develop four new NCF composite materials and the tensile and compression behavior of the newly developed NCF materials was experimentally investigated.

TL;DR: In this article, the International Standard ISO 13997 cut test method consists in measuring the distance that a straight blade slides horizontally to cut through a material under a constant applied normal force and was used to investigate cutting phenomena.

TL;DR: In this article, it was found that under the thermal cycle loading two interrelated processes take place in the material inner layers redistribution of dislocation and formation of sufficiently stable structure with less dislocation density.

TL;DR: In this article, the authors discuss the scattering of stress waves by defects in representative aircraft structures with multi-layered construction and geometry variation, and suggest that a computer solution of the problem may be required to determine the optimal combination of frequency and sensor location.

TL;DR: In this paper, the authors examined cracking in D6ac and 4340 steel along with Mil Annealed and STOA Ti-6Al-4V and found that the data implies that in the Paris Region (Region II) of the crack growth curve there is only a minimal R ratio dependency.

TL;DR: In this article, two 3D analytical models are proposed for the determination of mechanical properties of closed and open-cell foams under compression load, and fracture analysis is conducted based on the energy density concept and results are given for distortion and dilatational effects.

TL;DR: In this paper, the cracking characteristics of mixed mode dislocations near a lip-like mode crack, stress intensity and strain energy density factor are obtained by using conformal mapping, singularity analysis and Cauchy integrals.

TL;DR: In this paper, a theoretical analysis on the potential question in the quasi-static method is presented, then a novel algorithm is proposed which takes into account the inertia effect due to unstable crack propagation and meanwhile requests much lower computational efforts than purely dynamic method.

TL;DR: In this article, the dynamic crack propagation problem of I/II mixed mode crack in an infinite anisotropic body is investigated, and the critical strain energy density is determined by the strength parameters of an isotropic materials.

TL;DR: In this article, a multilayer film stresses model is derived to evaluate the residual stress distributions in the constitutive film layers of a ZnO pyroelectric sensor, which can be used to quantitatively analyze the film stresses and proceed to the optimization of thin film deposition process.

TL;DR: In this paper, the authors present results of simulation of quasi-static process of fracture in composite using cellular automata and fractal characteristics of defects growth based on box-counting method.

TL;DR: In this article, the effect of the thermal uncertainty encountered during the thermal numerical analysis on the out-of-plane angular distortion of the welded panels was investigated by employing data from numerical results using the finite element method and laboratory experimental measurements.

TL;DR: In this article, the authors proposed a new approach for shape optimisation with fatigue life as the design objective, which leads to the generation of a ‘near uniform’ fatigue critical surface.

TL;DR: In this article, the influence of plastic yielding and fracture on the entropy change in polypropylene having different morphologies, induced by different cooling rates during molding, was discussed and the results suggest that plastic deformation implies more cooperative segmental motions for higher crystalline content, which result in higher values of the preexponential factor containing the entropy term.

TL;DR: In this article, an integrated computer code is used for the simulation of the damage progression of a laminated fiber-reinforced composite stiffened plate with [0/90/plus or minus 45]s plies made of S-Glass/epoxy.

TL;DR: In this paper, the authors show that the global fracture energy criterion is not suitable to address the local release of energy because it includes the overall energy which are irrelevant to fracture initiation being a local behavior.

TL;DR: In this article, an elasto-anisotropic damage constitutive model for concrete is developed, in which the critical fracture stress and fracture toughness are investigated for materials with a single fractal crack based on the fractal geometry and the Griffith fracture criterion.