For the analysis of composite media, three different compatible and mixed finite element formulations are presented which apriori enforce the continuity of stresses as well as displacements at the element interfaces. The formulations are applied for the analysis of hi-material interfaces in two problems often encountered in the field of orthopaedic biomechanics, that is the fixation analysis in...

In damage detection the number of elements is generally more than the number of measured frequencies. Consequently, the corresponding damage detection equation is undetermined and thus has infinite solutions. Since in the damaged structures most of their elements remain healthy, the sparsest solution for the damage detection equation is mostly the actual damage. In the proposed method, the dama...

In this paper, the finite element analysis of two-dimensional linear viscoelastic problems is performed using quadrilateral complex Fourier elements and, the results are compared with those obtained by quadrilateral classic Lagrange elements. Complex Fourier shape functions contain a shape parameter which is a constant unknown parameter adopted to enhance approximation’s accuracy. Since the iso...

introduction: with the rapid increase in use of lasers in medical treatments, it is important to understand the mechanisms of heat transfer in biological tissues in order to minimize damage to the tissues resulting from extra heat applied. the aim of this study is to investigate the temperature distribution in living biological tissues when laser irradiation is used in a treatment. methods:  in...

afinite element model is developed for simulation of the curing process of a thick axisymmetric rubber article reinforced by metal plates during the molding and cooling stages. the model consists of the heat transfer equation and a newly developed kinetics model for the determination of the state of cure in the rubber. the latter is based on the modification of the well-known kamal-sourour mode...

This study is concerned with the formulation of three dimensional mapped infinite elements with 1/r and 1/ decay types. These infinite elements are coupled with conventional finite elements and their application to some problems of soil structure interaction are discussed. The effeciency of the coupled finite-infinite elements formulation with respect to computational effort, data preparation a...

micro-electro-mechanical systems (mems) are combination of electrical and mechanical components in micron dimensions. in recent years, holding, actuating methods and handling of mems components such asmicrogripper, microsensors and etc. have been deeply studied. microgrippers for handling, positioning andassembling of micro components are very useful so that for clamping need actuation created ...

Multigrid finite-element solvers using the corotational formulation of finite elements provide an attractive means for the simulation of deformable bodies exhibiting linear elastic response. The separation of rigid body motions from the total element motions using purely geometric methods or polar decomposition of the deformation gradient, however, can introduce instabilities for large element ...

in recent years, in order to reducing die design and manufacturing costs, multi point forming technique has gained an increasing interest because of its high flexibility. in this process, the conventional fixed shape solid die sets are replaced with a pair of opposite matrices of controllable elements. in this paper, the fundamental principles of multi-point forming was described and the possib...

in this paper, a new smooth second order sliding mode control is proposed. this algorithm is a modified form of super twisting algorithm. the super twisting guarantees the asymptotic stability, but the finite time stability of proposed method is proved with introducing a new particular lyapunov function. the proposed algorithm which is able to control nonlinear systems with matched structured u...