A series of molecular-dynamics simulations using a many-body interatomic potential has been performed to investigate the behavior under load of several ^001& and ^011& symmetrical tilt grain boundaries ~GB’s! in diamond. Cohesive energies, the work for fracture, maximum stresses and strains, and toughness as a function of GB type are evaluated. Results indicate that special short-period GB’s po...

A family of interatomic potentials is constructed for which the intrinsic ductility can be tuned systematically. Specifically, the elastic constants and critical energy release rate for Griffith cleavage, GIc, are held constant, while the critical energy release rate for dislocation emission, GIe, can be varied. This behavior is achieved by modifying a standard near-neighbor pair potential; the...

the problem of several finite moving cracks in a functionally graded material is solved by dislocation technique under the condition of anti-plane deformation. by using the fourier transform the stress fields are obtained for a functionallygraded strip containing a screw dislocation. the stress components reveal the familiar cauchy singularity at thelocation of dislocation. the solution is empl...

In this paper, the solution of a moving Volterra-type screw dislocation in an orthotropic layer, bonded between two piezoelectric layers is obtained using complex Fourier transform. The dislocation solution is then employed as strain nuclei to derive singular integral equations for a medium weakened by multiple moving cracks. These equations, which are classified as, Cauchy singular equations, ...

Phase-field fracture simulations have been established to simulate crack propagation in solid structures. The method employs a variational framework which has proven converge Griffith' classical model for brittle fracture. Here we investigate the predictiveness of phase-field through four-point bending test mixed mode condition, and discuss possibilities perform such simulation with finite elem...

We revisit in a 2d setting the notion of energy release rate, which plays a pivotal role in brittle fracture. Through a blow-up method, we extend that notion to crack patterns which are merely closed sets connected to the crack tip. As an application, we demonstrate that, modulo a simple meta-stability principle, a moving crack cannot generically kink while growing continuously in time. This la...

In this paper, a two-dimensional computational model is proposed for predicting the initiation position and propagation path of subsurface crack of spur gear tooth flank. In order to simulate the contact of teeth, an equivalent model of two contacting cylinders is used. The problem is assumed to be under linear elastic fracture mechanic conditions and finite element method is used for numerical...

in this paper, the solution of a moving volterra-type screw dislocation in an orthotropic layer, bonded between two piezoelectric layers is obtained using complex fourier transform. the dislocation solution is then employed as strain nuclei to derive singular integral equations for a medium weakened by multiple moving cracks. these equations, which are classified as, cauchy singular equations, ...

This study aims to characterise fatigue cracking of two types waste-derived (bio-oil and LDPE) bitumen. Modified Paris’ law Griffith criterion were proposed investigate crack propagation initiation the Results show that bio-oil delays LDPE accelerates initiation, bitumen itself dominates unaged The did not take effects in altering bitumen’s performance after pressure ageing vessel (PAV) ageing....

Infra-red video sequences were taken of directly bonded silicon wafer pairs undergoing the razor blade crack length test for bond strength in a specially designed jig. A series of tests were carried out under controlled atmospheres of nitrogen at various relative humidities. Analysis of the video images showed that the crack continues to propagate rapidly for several minutes after the blade has...