The problem of semi-infinite crack situated in an orthotropic strip sandwiched between two identical half planes has been considered. The considered boundary value problem has been solved to convert it into the standard Wiener-Hopf equation by using Fourier transform technique, which has been solved to obtain analytical expressions for stress intensity factor and crack opening displacement. The variations of stress intensity factors and crack opening displacement are displayed graphically for different pair of orthortropic materials and for various depth of the strip of the composite media.

This paper introduces a new approach to calculate stress intensity factors based on a combination of Displacement Extrapolation Method and Peridynamic Theory. After obtaining the displacement field from Peridynamic Theory, by appropriately selecting nodes at the crack tip region and their displacements yield stress intensity factors at the crack tips. To demonstrate the capability of the proposed approach, three different benchmark problems are considered including plate with a central crack, plate with an edge crack and plate with a slanted crack. Results evaluated from the current approach are compared against analytical and finite element analysis results, and good agreement is obtained between three different approaches. This shows that coupled Displacement Extrapolation Method and Peridynamic Theory approach can be an alternative method to calculate stress intensity factors.

Fracture analysis is performed on a cylindrical composite consisting of an outer elastic layer, an inner rigid cylinder and an intermediate sliding interface. Interaction between the sliding interface and a parallel crack under in-plane shear is explored. An interesting phenomenon of oscillatory normal stress occurs on the local interfacial region near to the crack. It leads to local sliding-prevention and promotion effects, which constitute the mechanisms for the variations of stress intensity factors versus interfacial parameters. In addition, another interesting conclusion is that a crack near and parallel to a sliding interface never has the conventional anti-symmetry, even under pure in-plane shear loading.

Abstract-The dynamic stresses around three collinear cracks in an infinite orthotropic plate are solved. In this configuration, two equal cracks are situated symmetrically on either side of a central crack, and time-harmonic elastic waves impinge perpendicularly to the cracks. The problem is solved by superimposing two types of solutions. One solution is that for a crack in an infinite orthotropic plate, and the other is for two collinear cracks. The unknown coefficients in the superimposed solution are determined by applying the boundary conditions at the surfaces of the three cracks using the Schmidt method. The dynamic stress intensity factors are calculated numerically for an orthotropic plate that corresponds to the elastic properties of a boron-epoxy composite.

A Plate Infinite Element Method (PIEM) formulation based on Reissner-Mindlin theory is proposed for the stress analysis of cracked plates under bending and tension. The validity of the proposed formulation is demonstrated by comparing the results obtained for the normalized Stress Intensity Factor (SIF) under various loading conditions with the solutions presented in the literature. Importantly, the proposed formulation enables the effects of different crack lengths to be analyzed without the need to re-mesh the computational domain for each simulation/analysis. Overall, the PIEM formulation provides an accurate and computationally-efficient means of analyzing a wide variety of plate bending problems.

In this study, numerical models based on finite-element method are developed for severalapplications of fracture mechanics. The use of cracked specimens formed by differentmaterial properties has allowed us to analyse the effect of the crack position to theinterface and to have a well understanding of mismatch effect for the case of mixed modeof fracture. In other hand, we have noticed that it is very interesting to see the effectof the interface position and loading for the case of symmetrically cracked ring specimenunder compression loading.

An efficient boundary weight function method for the determination of mode I stress intensity factors in a three-dimensional cracked body with arbitrary shape and subjected to arbitrary loading is presented in this study. The functional form of the boundary weight functions are successfully demonstrated by using the least squares fitting procedure. Explicit boundary weight functions are presented for through cracks in rectangular finite bodies. If the stress distribution of a cut out rectangular cracked body from any arbitrary shape of cracked body subjected to arbitrary loading is determined, the mode I stress intensity factors for the cracked body can be obtained from the predetermined boundary weight functions by a simple integration. Comparison of the calculated results with some solutions by other workers from the literature confirms the efficiency and accuracy of the proposed boundary weight function method.