We introduce a new, efficient approach for modelling the deformation of organs following surgical cuts, retractions, and resections. It uses the extended finite element method (XFEM), recently developed in ”fracture mechanics” for dealing with cracks in mechanical parts. XFEM eliminates the computationally-expensive remeshing that would be required if the standard finite element method (FEM) wa...

The finite element procedure is developed for the solution of three-dimensional geometrically nonlinear problems with small strains and large rotational and translational displacements. Updated Lagrangian formulation is used with controlling strains and stresses at local coordinate frames at element integration points. Equilibrium iterations at each step are performed according to the Newton-Ra...

The paper concerns numerical modelling of complicated GeoTechnical problems as mine stability, performance of underground radioactive waste repositories or microstructure modelling of geocomposites. The modelling uses finite elements and parallel computing based on overlapping domain decomposition. Important implementation issues for this approach are discussed: inexact solution of subproblems,...

We introduce a mixed discontinuous/continuous finite element pair for ocean modelling, with continuous quadratic layer thickness and discontinuous velocity. We investigate the finite element pair applied to the linear shallow-water equations on an f -plane. The element pair has the property that all geostrophically balanced states which strongly satisfy the boundary conditions have discrete div...

Displacement finite element models of various beam theories have been developed using traditional finite element interpolations (i.e., Hermite cubic or equi-spaced Lagrange functions). Various finite element models of beams differ from each other in the choice of the interpolation functions used for the transverse deflection w, total rotation φ and/or shear strain γxz, or in the integral form u...

The stress distribution in the vicinity of connections in a bolted steel angle is non-uniform because of the coupled effects of connection eccentricity, shear lag and stress concentrations. Although, some researchers have attempted finite element analysis, stipulations in various codes and specifications regarding the design of angle tension members are primarily based on the experimental studi...

Electrical impedance tomography is an imaging method, with which volumetric images of conductivity are produced by injecting electrical current and measuring boundary voltages. It has the potential to become a portable non-invasive medical imaging technique. Until now, implementations have neglected anisotropy even though human tissues such as bone, muscle and brain white matter are markedly an...

Finite-element modelling is a standard way for simulation of soft tissue deformation. For proper modelling, triangular surface models must fulfil requirements of accuracy, smoothness, and conciseness. Several techniques proposed in the literature do not meet these requirements. In this paper we extend a new technique called SurfaceNets, which can create a globally smooth triangle mesh that reta...

Mechanical and thermal modelling of the first normally-closed Parylene valve operating on electrothermal principles for rapid and wireless drug delivery was investigated. The modelling and experimental results confirm the mechanical robustness of the valve membrane. Valve opening behavior obtained by transient thermal finite element analysis are in accordance with the experimental microscopic i...