finite element method

In this article, we present and study a new coupled model combining the biological and the mechanical aspects describing respectively the process of the biogas production and the compressible two-phase leachate-biogas flow during the anaerobic biodegradation of organic matters in a landfill, which is considered a reactive porous medium.  The model obtained is governed by a reaction-diffusion system for the bacterial activity coupled with a compressible two-phase flow system of a non-homogeneous porous medium.  We carry out the analysis and the numerical approximation of the model within a v

Currently topology optimization is widely used by engineers for different practical problems.  Researches by different authors offer algorithms of using cellular automata in these problems, and most recent publications introduce a mesh-refinement procedure to decrease numerical efforts.  In this article, we propose to apply a mortar finite element method for solving topology optimization problems using cellular automata.  This methodology enables us to handle the non-conforming meshes, which can arise in the refinement process.  We present a formulation of the algorithm and analyse its comp

This article dwells upon the multiscale elastic structures consisting of matrix medium and thin coatings or inclusions.  The matrix medium is described by the equations of classical elasticity theory, while Timoshenko shell theory is used for the description of the thin parts of the structure.   On the interface between media, perfect contact conditions are assumed to hold.  The coupled algorithm is developed, based on the boundary element method in the matrix part and on the high order finite element method in the thin parts of the structure.  The two methods are coupled using a domain dec

The article develops a mathematical model of non-isothermal moisture transfer and viscoelastic deformation of wood during drying, which takes into account the anisotropy and variability of heat-mechanic characteristics. By finite element method was formulated by the implementation of mathematical models for viscoelasticity with regard to the accumulation of irreversible deformation. By object-oriented analysis is designed and implemented software implementation model in the form of documented classes.

Domain decomposition algorithm for solving problems of elasticity based on parallel computing is considered. The global system of equations for the entire domain is not formed and is represented by local matrices and vectors for subdomains using Boolean matrices of connectivity. The system of linear equations is solved by modified conjugate gradient method. The algorithm is implemented with C ++ using parallel MPI library. The results of testing proposed approach for modeling example are included.

In order to confirm the possibility of using the method of Nakamura in the study of surface layers of unknown structure, the authors carried out a comparative analysis of solid amplitude-frequency response research by both of modified Nakamura’s technique and finite element method on the estimating dynamic characteristics of surface layers.

The analysis of the design and drawing punch, which provides flexible parts during it`s production stamping. Special attention is paid to the analysis of the punch options, which are the process of changing operating conditions. The construction of the punch, which maintains altered conditions was offered.

The article presents an example of the usage of golden section search to select the comb length of MEMS el electro-actuator to get the desired displacement at a given voltage heating. The proposed solutions are implemented as software code in the ANSYS system.

A method for estimating and predicting abnormal layer and pore pressure during drilling of oil and gas wells using finite element method is elaborated. Utilizing simulated stress-strain state of a real model of a massif it is shown the qualitative agreement of results with theoretical calculations. We identified evaluation and prediction of pore and layer pressures and reservoir in the rock massif.