statement of problem: it is yet unclear whether fiber-reinforced composite posts can enhance the mechanical properties and prevent vertical fractures of teeth under chewing loads. purpose: the purpose of this study was to compare the fracture resistance and failure mode of endodontically treated teeth restored with three different post systems. materials and methods: thirty-six maxillary canine...

An investigation into the mixed mode fracture of steel fiber reinforced concrete (SFRC)beams with one percent volume fraction of steel fiber is presented. A series of notched beams withdifferent notch depths and locations are tested under three-point bending. The test results for apparentfracture toughness, crack trajectories, and fracture energy are presented. The crack paths for SFRCand plain...

1359-835X/$ see front matter 2008 Elsevier Ltd. A doi:10.1016/j.compositesa.2008.03.011 * Corresponding author. Tel.: +1 617 252 1539. E-mail address: [email protected] (B.L. Wardle). An interlaminar reinforcement using aligned carbon nanotubes (CNTs) is demonstrated for prepreg unidirectional carbon tape composites. Aligned CNTs are grown at high temperature and then transferprinted to prepreg at...

The toughness of Fe-based bulk metallic glasses BMGs has been significantly improved via systematic changes in chemistry. Chemistry changes were selected based on their likely effects on critical elastic constants shown to affect plasticity/toughness in various BMGs, in addition to their recently discovered effects on chemical bonding in these Fe-based systems. The fracture energy obtained on n...

In this paper, effects of ply orientation of adjacent plies with (ϕ//θ) interfaces on mode II critical strain energy release rate (fracture toughness) of multidirectional (MD) laminate has been studied. Ply orientation of adjacent plies is one of the most important parameters affects the mode II critical strain energy release rate () in the initiation of the delamination. To  study this paramet...

For crack growth along an interface between dissimilar materials the effect of combined modes I, II and III at the cracktip is investigated. First, in order to highlight situations where crack growth is affected by a mode III contribution, examples of material configurations are discussed where mode III has an effect. Subsequently, the focus is on crack growth along an interface between an elas...

A mechanical model for the prediction of mode I delamination failure of a laminated double cantilever beam (DCB) type specimen is presented. The volume of material ahead of the crack tip that experiences high stresses due to the presence of the crack tip was replaced by a nonlinear elastic spring foundation. The volume undergoing global deformation due to the external loading was replaced by a ...

This paper deals with the determination of the effect of varying material properties on the value of the stress intensity factors, KI and KII, for anisotropic plates containing cracks and subjected to a temperature change. Problems involving cracks and body forces, as well as thermal loads are analysed. The quadratic isoperimetric element formulation is utilized, and SIFs may be directly obtain...

Mode I steady crack growth was analyzed to determine the toughening due to domain switching in ferroelectric ceramics. A multi-axial, electromechanically coupled, incremental constitutive theory is applied to model the material behavior of the ferroelectric ceramic. The constitutive law is then implemented within the finite element method to study steady crack growth. The effects of mechanical ...