A long matrix crack in a unidirectional bre{reinforced composite, perpendicular to the bre direction and subjected to Mode{I loading, is considered. The intact composite material is modelled as homogeneous linearly elastic and the bridging bres are replaced by restraining tractions acting on the crack surfaces. The problem is formulated in terms of a hypersingular integral equation with respect...

Firstand second-order asymptotic solutions are given for the problem of a Mode I crack rapidly propagating in an elastic}viscoplastic solid. Results are obtained for the order of the crack-tip singularity, the angular position at which unloading occurs, and the angular variations of stresses and velocities. It is shown that the eigenvalue, which determines the order of stress singularity, relat...

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...

Micromechanical methods to predict the fracture behavior and estimate the fracture toughness of cellular solids and foams are presented in this paper. The microstructure of the foam is modeled using finite elements. The struts of foam are modeled using either structural elements such as beams or three-dimensional solid elements. A portion of the foam containing an edge crack is modeled. Displac...

Modeling strain localization with a second gradient model can become problematic at the late stages of softening response, when terms significant compared to first terms. This is particularly true for mode I crack problems where an unrealistic spreading localized zone be encountered. To deal these limitations, novel interface element propagation introduced. It shown that able correctly reproduc...

We present a non-dimensional analytical model for crack propagation in a z-pinned double cantilever beam specimen (DCB) under mode I loading. Effect of various design parameters on the crack bridging length and apparent fracture toughness are investigated using this model. The efficacy of the analytical model is evaluated by comparing the results with 3D finite element (FE) simulations of the D...

An evaluation of the fatigue crack resistance of human dentin was conducted to identify the degree of degradation that arises with aging and the dependency on tubule orientation. Fatigue crack growth was achieved in specimens of coronal dentin through application of Mode I cyclic loading and over clinically relevant lengths (0 ≤ a ≤ 2 mm). The study considered two directions of cyclic crack gro...

In this paper, the stress intensity factor (SIF) variations along an arbitrarily developing crack front, the non-planar fatigue-crack growth patterns, and the fatigue life of a round bar with an initially straight-fronted surface crack, are studied by employing the 3D symmetric Galerkin boundary element method-finite element method (SGBEM-FEM) alternating method. Different loading cases, involv...