This paper describes a combined fracture–plastic model for concrete. Tension is handled by a fracture model, based on the classical orthotropic smeared crack formulation and the crack band approach. It employs the Rankine failure criterion, exponential softening, and it can be used as a rotated or a fixed crack model. The plasticity model for concrete in compression is based on the Menétrey–Wil...

Various analytical methods based on the real reciprocity relation are applied to the problem of Rayleigh wave scattering by a surface crack. In one formulation, the reflection coefficient observed at the transducer terminals is expressed in terms of an integral over the crack surface of the product of the perturbed and unperturbed fields. This integral is then converted to a volume integral and...

A nominally straight crack of finite length is subjected to plane-strain loadings. A perturbation method is developed for calculating the stress-intensity factors, based on an asymptotic analysis of the governing hypersingular boundary integral equation for the crack-opening displacement. Known exact results for a shallow circular-arc crack are recovered, correct to second order in the small ge...

190 Abstract In this paper, a new analytical method for solving stable crack propagation problems in a ductile panel with a row of cracks, is presented. The main purpose of the present study is to estimate the maximum load carrying capacity of such panels accurately. The so called Elastic Plastic Finite Element Alternating Method (Pyo et al. (1994)) was extended to account for the propagating c...

Derivation of the integral equation for general 3D crack problems was examined based on the theory of body force method. In the present analysis, stress intensity factors (SIFs) along a front of arbitrary shaped 3D planar crack are obtained directly only by solving simultaneous equations expressing a boundary condition. The crack surface is discretized using number of triangular elements and th...

During crack growth of real materials, the total energy released can be partitioned into elastic and dissipative terms. By analyzing material models with mechanisms for dissipating energy and tracking all energy terms during crack growth, it is proposed that computer simulations of fracture can model crack growth by a total energy balance condition. One approach for developing fracture simulati...

This paper treats the interactions between a main crack and a rnicrocrack in an anisotropic piezoelectric solid. Based on the Green's function approach and the principle of superposition, a system of singular integral equations for the unknown temperature discontinuity defined on each crack face is developed and can be solved numerically. In the analysis, the residual heat flux, stress and elec...

conclusions vacuum-assisted abdominal closure is a good technique for temporary abdominal closure. in patients who are unable to achieve fascial closure, skin closure alone is safe. results after 157 trauma laparotomies, 35 (22%) were open abdomen cases with an average injury severity score was 35. ninety-four percent of open abdomens occurred after damage-control surgery. temporary vacuum-assi...

In this paper the general problem of a rectangular plate clamped along two parallel sides and containing a crack parallel to the clamps is considered. The problem is formulated in terms of a system of singular integral equations and the asymptotic behavior of the stress state near the corners is investigated. Numerical examples are considered for a clamped plate without a crack and with a centr...