In this paper, a positive definite semi-discrete mixed finite element method was presented for two-dimensional parabolic equations. In the new positive definite systems, the gradient equation and flux equations were separated from their scalar unknown equations.  Also, the existence and uniqueness of the semi-discrete mixed finite element solutions were proven. Error estimates were also obtaine...

The Extended Finite Element Method (XFEM) is a technique used in fracture mechanics to predict how objects deform as cracks form and propagate through them. Here, we propose the use of XFEM to model the deformations resulting from cutting through organ tissues. We show that XFEM has the potential for being the technique of choice for modelling tissue retraction and resection during surgery. Can...

A Finite Element Method (FEM) mesh is converted to a reluctance network through an original magnetostatic formulation based on face shape functions. This meshed reluctance network is coupled with an standard one, characterizing a 0D system. Both approaches are fully-compatible and the hybridized problem can be solve with a single circuit solver. The approach is tested in 2D on a magnetic circui...

Mechanical properties of rocks with inclusions, which may correspond to porous rocks under limiting conditions, are influenced by their shape, distributions, and intrinsic properties. Many different averaging methods such as homogenization, micro-mechanics and microstructure methods are proposed to estimate average thermo-hydro-mechanical properties of rocks. In this paper, the authors evaluate...

O. Chivu, C. Rontescu, D-T. Cicic, Polytechnic University of Bucharest, Romania This paper presents the results of the practical trials carried out based on the calculation assumptions considered within the FEM of the reconditioning by welding of a crankshaft used in the automotive industry. For the validation of the analytical model it was considered the influence of the crankshaft fixing poss...

The finite element method (FEM) is used to study the influence of porosity and pore shape on the elastic properties of model porous ceramics. The Young’s modulus of each model was found to be practically independent of the solid Poisson’s ratio. At a sufficiently high porosity, the Poisson’s ratio of the porous models converged to a fixed value independent of the solid Poisson’s ratio. The Youn...

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...

Good slip resistant tread patterns of outer-sole of military boot are vital to minimize the risk or severity of slip in combat and physical training situations. A series of non-linear, three-dimensional finite element analyses of footwear and ground interaction based upon the Drucker-Prager elastic-perfectly plastic material model was investigated. This study was aimed at how plastic failure of...