The mechanisms of fatigue-crack propagation are examined with particular emphasis on the similarities and differences between cyclic crack growth in ductile materials, such as metals, and corresponding behavior in brittle materials, such as intermetallics and ceramics. This is achieved by considering the process of fatiguecrack growth as a mutual competition between intrinsic mechanisms of crac...

The time variation of crustal velocities in tectonic regions is most reasonably attributed to stressinduced variations in crack porosity. The decrease in V•,/Vs before arthquakes is due primarily to a large decrease in Vp. This supports the Nur dilatancy hypothesis but not the effective stress hypothesis. New data from the San Fernando region verify the Vp drop, show that this drop cannot be en...

Finite element analysis of the delamination crack propagation in laminated composites is presented. Fracture mechanics based Virtual Crack Closure Technique (VCCT), and the cohesive element technique, have been used to simulate the delamination initiation and propagation under Mode-I type loading. Detailed description of the parameter selection process for these two techniques with ABAQUS®/Stan...

In this study, based on a regression of the crack tip displacements, the stress intensity range in fatigue is quantitatively determined for the shape memory alloy Ni2FeGa. The results are compared to the calculated stress intensity ranges with a micro-mechanical analysis accounting for the transformation-induced tractions. The effective stress intensity ranges obtained with both methods are in ...

In this paper a new method to determine the fracture properties and strain energy release rate for Carbon- Polyester composite has been introduced.  Fracture characteristics such as critical stress intensity factor and critical strain energy release rate for mode I, mode II and mixed mode loading were determined using Arcan type specimen. 130 layers of carbon fiber polyester woven composite wit...

Fatigue and fracture mechanisms have been studied in a steel-based metal matrix composite (MMC), comprising a 316L austenitic matrix reinforced with 25 wt% particulate titanium diboride (TiB2). The fracture toughness was determined in the as-HIPped condition as being slightly below 30 MPa√m. Fatigue crack growth rates have been determined, and corrected for the effects of crack closure. The fra...

A self-healing, metal matrix composite reinforced by shape memory alloy wires is simulated using finite element analysis. A one-dimensional constitutive model for SMA behavior is implemented as a user-defined truss element in ABAQUS. The matrix is brittle and a mode I crack is allowed to propagate through the specimen upon loading. During the loading process the wires undergo a martensitic phas...