We consider the task of resolving accurately the nth eigenpair of a generalized eigenproblem rooted in some elliptic partial differential equation (PDE), using an adaptive finite element method (FEM). Conventional adaptive FEM algorithms call a generalized eigensolver after each mesh refinement step. This is not practical in our situation since the generalized eigensolver needs to calculate n e...

INTRODUCTION The finite element method (FEM) is an engineering resource applied to calculate the stress and deformation of complex structures, and has been widely used in orthodontic research. With the advantage of being a non-invasive and accurate method that provides quantitative and detailed data on the physiological reactions possible to occur in tissues, applying the FEM can anticipate the...

build full size prototypes and test and measure the stresses (with strain gauges, etc) A general overview of the use of the Finite Element Method (FEM) is given. It describes how FEM supplements industry use FEM. design codes when dealing with non-standard shapes or The first mentioned choice is on one hand risky and on the complex loading conditions. It covers the reasons for the use other may...

Finite Element Methods (FEM) play an important role in modelling of complex systems. Models generated from FEM are of very high dimension and are difficult to handle for control system design. In this paper, an algorithm is presented that converts a system generated from FEM into the state space model of an interconnected system, thus vastly reducing the complexity of synthesizing a distributed...

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...

Electrical impedance tomography (EIT) of closed conductive media is an ill-posed inverse problem. In the general case, the resolution of the direct problem, derived from a second order partial derivative equation, requires a numerical approximation. The solution brought by the Finite Element Method (FEM) is often used in EIT, because it preserves the nonlinear dependence of the observation set ...

BACKGROUND The finite element method (FEM) is a powerful mathematical tool to simulate and visualize the mechanical deformation of tissues and organs during medical examinations or interventions. It is yet a challenge to build up an FEM mesh directly from a volumetric image partially because the regions (or structures) of interest (ROIs) may be irregular and fuzzy. METHODS A software package,...

Experiments of crack propagation in rubbers have shown that a discontinuous jump of crack propagation velocity can occur as energy release rate increases, which is known as the "mode transition" phenomenon. Although it is believed that the mode transition is strongly related to the mechanical properties, the nature of the mode transition had not been revealed. In this study, dynamic crack propa...

Terrestrial laser scanning technology (TLS) is a new technique for quickly getting three-dimensional information. In this paper we research the health assessment of concrete structures with a Finite Element Method (FEM) model based on TLS. The goal focuses on the benefits of 3D TLS in the generation and calibration of FEM models, in order to build a convenient, efficient and intelligent model w...