a two-dimensional (2d) single particle model for the copolymerization of propylene-ethylene with heterogeneous ziegler-natta catalyst is developed. the model accounts for the effects of the initial shape of the catalyst and carck/ pore patterns on the copolymer composition, polymerization rate and the average molecular weight properties. the spherical and oblate ellipsoidal shapes of catalyst p...

Introduction: The aim of this study was to evaluate the effect of proximal contour of class II composite restorations placed with straight or contoured matrix band using composite resins with different modulus of elasticity on stress distribution by finite element method. Methods: In order to evaluate the stress distribution of class II composite restorations using finite element method, upper ...

In this paper, we investigate a relatively new method for determining three-dimensional sub-surface residual stress (Ueda, 1975). This hybrid experimental/analytical method determines the source of residual stress by sectioning and strain measurement, and then uses it to deduce residual stress in the original body. When certain assumptions about the spatial distribution of the source of residua...

Residual stresses have become an important player in the field of the structural integrity for many years. Having an exact knowledge of residual stress distributions can be essential in designing the engineering components as unexpected failures are inevitable where such stresses are ignored.  There are many residual stresses measurement techniques including destructive and non-destructive ones...

By using finite element analysis, we proposed an applicable finite element method of laser shock peening (LSP) and discussed various parameters, such as solution time, stability limit, dynamic yield stress, peak pressure, pressure pulse duration, laser spot size, and multiple LSP. The effects of parameters related to the finite element simulation of the LSP process on the residual stresses of 3...

the finite element method is employed for the flexural-torsional linear buckling analysis of beams of arbitrarily shaped composite cross-section taking into account generalized warping (shear lag effects due to both flexure and torsion). the contacting materials, that constitute the composite cross section, may include a finite number of holes. a compressive axial load is applied to the beam. the...

Abstract. A hybrid stress finite volume method is proposed for linear elasticity equations. In this new method, a finite volume formulation is used for the equilibrium equation, and a hybrid stress quadrilateral finite element discretization, with continuous piecewise isoparametric bilinear displacement interpolation and two types of stress approximation modes, is used for the constitutive equa...

An extension of the contour integral method (CIM) for the computation of stress intensity factors for loaded cracks is presented. Numerical solutions of the two-dimensional linear elasticity equations are computed with the p-version of the generalized finite element method. Polynomial enrichment functions as well as enrichment with near crack tip asymptotic expansion are used. The robustness of...

The geometric optimization of orthopedic screws can considerably increase their orthopedic efficiency. Due to the high geometric parameters of orthopedic screws, a finite element simulation is an effective tool for analyzing and forecasting the effect of the parameters on the load-bearing capacity of different types of screws and bones. Thus, in the present study, the tensile strength of a typi...

Residual Stress measurement has gained interests among researchers for many years due to its great influence on the structural integrity. Slitting method is one of the destructive techniques that relies on the introduction of an increasing cut to a part containing residual stresses. Similar to all other mechanical strain relief techniques, slitting also suffers from its shortcomings during the ...