A numerical technique for modeling fatigue crack propagation of multiple coplanar cracks is presented. The proposed method couples the extended finite element method (X-FEM) [Int. J. Numer. Meth. Engng. 48 (11) (2000) 1549] to the fast marching method (FMM) [Level Set Methods & Fast Marching Methods: Evolving Interfaces in Computational Geometry, Fluid Mechanics, Computer Vision, and Materials ...

Abst rac t -The continuum constitutive modeling for rate-dependent fracture of brittle microcracking solids, which was described in Part 1 of this paper, is applied to the finite element analysis of stationary and nonstationary macrocracks in a single-edge-notched three-point bend specimen under a static loading. The microcrack damage zones near the macro-crack-tip can be classified as being "l...

We present a modeling technique for the interaction of an elliptical-shape crack in a metal with an open-ended waveguide. The crack is first modeled by an appropriate number of short rectangular waveguides. The mode-matching technique is then used to calculate the scattering matrix of the new segmented waveguide structure. The probe reflection coefficient of the dominant mode is finally calcula...

Vibrothermogrphy is a promising technique that uses ultrasonic elastic waves to locally stimulate defects on solids specimens and is typically applied in the aerospace and automotive industries. This technique allows for defect selective imaging using thermal waves that are generated by ultrasound waves. The mechanism involved is frictional heating or hysteresis that turns a dynamically loaded ...

A model has been developed to predict crack opening and closing behavior for propagating fatigue cracks which undergo significant sliding displacements at crack flanks. Crack surfaces were described statistically by assuming a random distribution of asperity heights and a mean density of asperities and asperity radii. The propagating crack was subdivided into strips, and each strip was treated ...

It is necessary to manage the fatigue crack growth (FCG) once those cracks are detected during in-service inspections. In this paper, a simulation program (FCG-System) is developed utilizing the commercial software ABAQUS with its object-oriented programming interface to simulate the fatigue crack path and to compute the corresponding fatigue life. In order to apply FCG-System in large-scale ma...

In welded tubular joints, when the fatigue crack depth is less than 20% of chord wall thickness, the crack growing process is highly affected by weld geometry.&#10 Hence, T-butt solution and weld magnification factor (Mk) are applicable tools for evaluating the crack growth rate in this domain. In this research, the capability of Artificial Neural Network (ANN) for estimating the Mk of weld toe...

In welded tubular joints, when the fatigue crack depth is less than 20% of chord wall thickness, the crack growing process is highly affected by weld geometry. Hence, T-butt solution and weld magnification factor (Mk) are applicable tools for evaluating the crack growth rate in this domain. In this research, the capability of Artificial Neural Network (ANN) for estimating the Mk of weld toe c...

a new approach is proposed to model a crack in orthotropic composite media using the extended finite element method (xfem). the xfem uses the concept of partition of unity in addition to meshless basic idea of approximating a field variable by its values at a set of surrounding nodes. as a result, higher order approximations can be designed with the same total number of degrees of freedom. in t...

Two levels of fidelity are used for minimum weight design of a composite bladestiffened panel subject to crack propagation constraints. The low fidelity approach makes use of an equivalent strain constraint calculated by a closed form solution for the stress intensity factor. The high fidelity approach uses the stress intensity factor directly as the constraint and computes it from the stress d...