Finite element analysis procedures are utilized to provide theoretical calibration curves for the electrical potential crack-monitoring system as applied to single-edge-notch (SEN) and compact tension (CT) fracture specimens. The results are compared to existing calibrations for such test piece geometries derived using experimental, electrical analog and analytical (conformal mapping) procedures.

The crack of a whip is produced by a shock wave created by the supersonic motion of the tip of the whip in the air. A simple dynamical model for the propagation and acceleration of waves in the motion of whips is presented. The respective contributions of tension, tapering, and boundary conditions in the acceleration of an initial impulse are studied theoretically and numerically.

Fracture toughness resistance curves describe a material's resistance against crack propagation. These curves are often used to characterize biomaterials like bone, nacre or dentin as these materials commonly exhibit a pronounced increase in fracture toughness with crack extension due to co-acting mechanisms such as crack bridging, crack deflection and microcracking. The knowledge of appropriat...

OBJECTIVES The objective of this in vitro study was to evaluate the fatigue crack growth properties of the dentin/resin adhesive interface. METHODS Compact tension (CT) specimens were prepared from coronal dentin, resin composite, and dentin bonded to resin composite using Optibond Solo Plus adhesive. All specimens were then subjected to cyclic Mode I loading while fully hydrated at a stress ...

Fatigue-crack-growth tests were conducted on compact, C(T), specimens made of D16Cz (clad) aluminum alloy under constant-amplitude loading, a single spike overload, and simulated aircraft spectrum loading. Constant-amplitude tests were conducted to generate crack-growth-rate data from threshold to near fracture over a wide range of stress ratios (R = Pmin/Pmax = 0.1–0.75) using the new compress...

The J-based fracture testing technique is newly extended to experimentally determine the tension-softening (a-6) relations in ceramic-matrix composites. The J-based technique originally proposed for concrete has been well established for quasi-brittle materials where the fracture process is primarily dominated by the formation of a fracture process zone and the contribution of the crack tip tou...

We study a class of models for brittle fracture: elastic theory models that allow for cracks but not for plastic flow. We show that these models exhibit, at all finite temperatures, a transition to fracture under applied load similar to the first-order liquid-gas transition. We study this transition at low temperature for small tension. Using the complex variable method in a two-dimensional ela...

in this paper the critical strain energy release rate for t300/913 carbon-epoxy laminated composites has been studied using ansys finite element software based on virtual crack closure technique ( vcct ). compact tension ( ct ) specimen has been used for numerical analyses and the geometrical dimensions have been extracted from the existing references. the results obtained from the finite eleme...

There are many ways that women support their use of crack cocaine, including sex-for-crack bartering and other forms of prostitution. Empirical studies conducted in the mid-1970s and in the mid-1980s in New York City, and in Chicago in the late 1980s to early 1990s are compared, analyzing similarities and differences between the contemporary crack-prostitution scene and previous prostitution sc...