A Porous Media Approach to Finite Deformation Behaviour in Soft Tissues.

The present work presents a porous medium formulation for the biomechanical analysis of soft tissues. An updated Lagrangian approach is developed to study the coupled effects of low speed flows of fluid phases, in partially or fully saturated conditions, and the finite deformation occurring in the solid matrix. The procedure developed allows both for the evaluation of coupled geometric and material non-linearities.

Investigation of the integration process of dental implants by means of a numerical analysis of dynamic response.

Objectives: The aim of this work was to present a preliminary numerical analysis of the integration process of dental implants using a finite element simulation of the dynamic response following impulse excitation. Assessment of the osseointegration process has been previously examined using a numerical approach by calculating the natural frequency of a cantilever attached to the implant. The methodology adopted in this work allows a direct measurement of the implant response following impulse loading and avoids the addition of a bulky cantilever set-up.

Adaptive finite-element approach for analysis of bone/prosthesis interaction.

The study uses the finite-element method to analyse the stress field in a perfectly bonded hip prosthesis arising from loading through body weight. Special attention is paid to the accuracy of the numerical analysis, and adaptive mesh refinement is introduced to reduce the discretisation error. The finite-element procedure developed is especially well suited to analyse the behaviour of a bonded interface as it is capable of calculating accurately the stress at the nodal positions while satisfying the natural discontinuity in the stress field at this location.

The mechanical behaviour of bony endplate and annulus in prolapsed disc configuration.

The mechanical response of intervertebral joints is deeply influenced by disc degeneration. The phenomenon is expressed in terms of variations in the biomechanical properties of the material, whose compressibility characteristics change because of the liquid content loss in the tissue and, what is even more important, to prolapse. In this work, the problem is investigated by means of a computational mechanics approach; a coupled material and geometric non-linear model is developed, representing vertebra, annulus and nucleus submitted to an axial load.

Nonlinear analysis of intervertebral disk under dynamic load.

This study pertains to the response of intervertebral joint under dynamic axial load. The numerical model represents two vertebral bodies with an interposed disk and uses three-dimensional elements. A transversely isotropic material law is adopted for cortical bone and an isotropic law for cancellous bone.