recent developments in nanostructured products draw considerable attention to ultrafine grained materials. these materials are normally manufactured by different severe plastic deformation (spd) methods. in the present study, analytical models and finite element method (fem) are used to calculate strain imposed to a specimen that was deformed by equal channel angular pressing (ecap). in additio...

This paper introduces a new method for accelerating current sluggish FEM and improving memory demand in FEM problems with high node resolution or bulky structures. Like most of the numerical methods, FEM results to a matrix equation which normally has huge dimension. Breaking the main matrix equation into several smaller size matrices, the solving procedure can be accelerated. For implementing ...

The development of numerical methods for solving the Helmholtz equation, which behaves robustly with respect to the wave number, is a topic of vivid research. It was observed that the solution of the Galerkin finite element method (FEM) differs significantly from the best approximation with increasing wave number. Many attempts have been presented in the literature to eliminate this lack of rob...

This report presents a voxel-based biomechanical model for muscle deformation using nite element method (FEM) and volume graphics. Hierarchical voxel meshes are reconstructed from ltered segmented muscle images followed by FEM simulation and volume rendering. Physiological muscle force is considered and linear elastic muscle models for both static and dynamic cases are simulated by FEM. Voxel-b...

Numerical 3D formulations using scalar  and vector A potentials are examined for magnetic fields, with emphasis on the finite difference (FDM) and finite element (FEM) methods using nodal and facet elements. It is shown that for hexahedral elements the FDM equations may be presented in a form similar to the FEM equations; to accomplish this the coefficients defining volume integrals in FEM nee...

The purpose of the present work was to construct the multiscale FEM model of artificial heart chamber composed of nanocoatings. This goal is reached by the development of the FEM macromodel of artificial blood chamber using the commercial code and by the creation of the micromodel based on our own FEM code. The latter uses strain state obtained after loading in macromodel. The loci of failure i...

Friction drilling uses a rotating conical tool to penetrate the workpiece and create a bushing in a single step without generating chips. This research investigates the threedimensional (3D) finite element modeling (FEM) of large plastic strain and hightemperature work-material deformation in friction drilling. The explicit FEM code with temperature-dependent mechanical and thermal properties, ...

Welding-induced deformation not only negatively affects dimension accuracy but also degrades the performance of product. If welding deformation can be accurately predicted beforehand, the predictions will be helpful for finding effective methods to improve manufacturing accuracy. Till now, there are two kinds of finite element method (FEM) which can be used to simulate welding deformation. One ...

Fixed and random effects models for longitudinal data are common in sociology. Their primary advantage is that they control for time-invariant omitted variables. However, analysts face several issues when they employ these models. One is the uncertainty of whether to apply the fixed effects (FEM) versus the random effects (REM) models. Another less discussed issue is that the FEM and REM models...

Three dimensional image reconstruction for multi-modality optical spectroscopy systems needs computationally efficient forward solvers with minimum meshing complexity, while allowing the flexibility to apply spatial constraints. Existing models based on the finite element method (FEM) require full 3D volume meshing to incorporate constraints related to anatomical structure via techniques such a...