The size-effect, two-parameter, and fictitious crack models were developed to predict crack growth in materials like concrete that experience tension softening. The three models must predict the same response for infinitely large structures. Therefore, this study evaluates the differences in response for smaller structures. The metric used to compare response is the fracture toughness value req...

Understanding the fatigue crack growth phenomenon in railheads requires a study of driving forces such as the crack tip opening and sliding displacements, under repeated rolling contact. Finite element simulations, allowing elastic-plastic deformation, and mixed-mode crack growth laws were utilized to demonstrate that the fatigue crack growth rates display a minimum after a finite amount of cra...

A line integral is exhibited which has the same value for all paths surrounding the tip of a notch in the two-dimensional strain field of an elastic or deformation-type elastic-plastic material. Appropriate integration path' choices serye bOlh to relate Ihe integral to the near tip deformatiot~s and, in many cases. to permit its direct e:tlalutllion. This (l.t'eraged measure of the near tip fie...

In this investigation ‚the fracture toughness of A356 containing15%SiC composite was studied. Al/SiC composites have been considered because of their mechanical and erosion properties .Low fracture toughness in Al/SiC as compared with Aluminium alloys is one of its disadvantage. In this study at first A356 alloy was melted in a smelting electrical furnace then poured into the mould. A356-15% Si...

in this work, the mechanism for fracture of brittle substances such as rocks under a uniform normal tension is considered. the oriented straight micro-cracks are mostly created in all the polycrystalline materials resulting from the stress concentrations. the present work focuses on the interactions of the pre-existing micro-cracks, which can grow and propagate within a rock-like specimen. the ...

Debonding of an inclusion from the surrounding matrix in the presence of a nearby crack tip is studied numerically. Finite element models of symmetric three-point bend configurations are implemented in conjunction with a stiffness degradation method and the maximum tensile stress criteria to investigate the influence of debonding on crack tip parameters. The geometry considered is a single edge...

The formulation for thermal stress and electric displacement in an in®nite thermopiezoelectric plate with an interface and multiple cracks is presented. Using Green's function approach and the principle of superposition, a system of singular integral equations for the unknown temperature discontinuity de®ned on each crack face is developed and solved numerically. The formulation can then be use...