The behavior of cleavage crack fronts at grain boundaries in free-standing silicon thin films is investigated through a microtensile experiment. In addition to the crystallographic orientation, the orientation of grain boundary plane also plays a critical role. With respect to the initial crack surface, if the inclination angle is relatively small, the crack tends to penetrate across the bounda...

Shear-wave splitting, observed in microearthquake records at The NW and SE Geysers geothermal fields, CA has proved to be effective in the detection of subsurface crack orientations and crack densities. Crust anisotropy due to patterns of stress-aligned fractures causes approaching shear-waves to split into fast and slow arrivals. Within the shear-wave window of a given seismic station, the mea...

This paper deals with the effect of several residual stress profiles on the fatigue crack propagation in prestressing steel wires subjected to tension loading or bending moment. To this end, a computer program was developed to evaluate the crack front evolution on the basis of the Walker law. Results demonstrate that the absence of residual stresses makes the crack propagate towards a preferent...

Analysis has been performed on fracture initiation near a crack in a brittle material with strength described by Weibull statistics. This nonlocal fracture model allows for a direct correlation between near crack-tip stresses and failure. Predictions are made for both the toughness and average fracture initiation angle of a crack under mixed-mode loading. This is pertinent for composites and is...

THE GENERAL weight function expressions given in GAO (J. Mech. Phys. Solids 37, 133, 1989). referred to here as part I, for combined-mode crack-dislocation interaction problems in the three-dimensional regime are applied to solve for the stress field and energy of a shear dislocation loop emerging from the tip of a half-plane crack. The results are compared to the previously proposed approximat...

A reliable and cost effective two-phase methodology is proposed to predict crack propagation in generic two-dimensional structural components under complex fatigue loading. First, the fatigue crack path and its stress intensity factors are calculated in a specialized finite element software, using small crack increments. At each crack propagation step, the mesh is automatically redefined based ...

This paper concerns the effect of friction on crack propagation for centrally cracked Brazilian disk under diametric forces by using a modified finite element method. It shows that mode II stress intensity factor decreases obviously with increase after is closed, while has no influence I and T-stress. Meanwhile, there are some significant influences due to change closed appropriate loading angl...

In this work, fracture behavior of multilayered unidirectional graphite/epoxy composite (T800/3900-2) materials is investigated. Rectangular coupons with a single-edged notch are studied under geometrically symmetric loading configurations and impact loading conditions. The notch orientation parallel to or at an angle to the fiber orientation is considered to produce mode-I or mixed-mode (mode-...

The filling of strand corrosion products during concrete crack propagation is investigated experimentally in the present paper. The effects of stirrups on the filling of corrosion products and concrete cracking are clarified. A prediction model of crack width is developed incorporating the filling proportion of corrosion products and the twisting shape of the strand. Experimental data on cracki...

The size and the character (low and large angle, special boundaries, tilt and twist boundaries, twins) of the grain boundaries (GBs) in polycrystalline materials influence their strength and their fracture toughness. Recent studies devoted to nanocrystalline (NC) materials have shown a deviation from the Hall-Petch law. Special GBs formed by Σ3 twins in face-centred cubic metals are also known ...