Cracks and craze lines are often observed in the enamel of human teeth, but they rarely cause tooth fracture. The present study evaluates fatigue crack growth in human enamel, and compares that to the fatigue response of sintered hydroxyapatite (HAp) with similar crystallinity, chemistry and density. Miniature inset compact tension (CT) specimens were prepared that embodied a small piece of ena...

Dynamic crack growth along a bimaterial interface under impact shear loading is analyzed numerically. The material on each side of the bond line is characterized by an isotropic hyperelastic constitutive relation. A cohesive surface constitutive relation is also speci®ed that relates the tractions and displacement jumps across the bond line and that allows for the creation of new free surface. ...

A study has been made of the fatigue-crack propagation properties of a series of laminated Nbreinforced Nb3Al intermetallic-matrix composites with varying microstructural scale but nominally identical reinforcement volume fraction (20 pct Nb). It was found that resistance to fatigue-crack growth improved with increasing metallic layer thickness (in the range 50 to 250 mm) both in the crack-divi...

Cracks are dangerous and frequently observed defects in steel structures. Therefore, the understanding of the mechanism of crack is very important to structure safety. Although the mechanism of static crack has been widely studied by researchers, the mechanism of dynamic crack has been left out and seldom been discussed. In this paper, a modeling method for acoustic emission (AE) source of dyna...

Despite decades of study, the atomic-scale mechanisms of fatigue crack growth remain elusive. Here we use the coupled atomistic–discrete dislocation method, a multiscale simulation method, to examine the influence of dislocation glide resistance on near-threshold fatigue crack growth in an aluminum alloy. The simulations indicate that the threshold increases with an increase in dislocation glid...

Crack: The tests were performed using Crack version 1.0 beta 18. Crack is a description logic system with both TBox and ABox, using the logic ALCRIFO. Crack reasoning procedures are based on a sound and complete tableaux algorithm 1].