Abstract

Understanding the total complexity of biomechanical/mechanical properties of the human skin and developing an advance computational model (e.g. the Finite element skin models) that do not differ (or not so much differ!) from experimental data would provide information which could be very useful for surgical training and practical use (special in this project, the goal is to inform the development of optimized device which can be used for effective and reproducible skin penetration in the clinical setting. This project will also provide clear definition of underlying mechanisms of penetration and cutting and make it possible of generating a robust computational and physical model and an excellent technique for measuring skin deformation and in combination with advanced computational/mechanical methods it will offer many possibilities for in vivo measurements).
Difficulties and solutions related to the experience of developing this project beside the fundamental limitation of the finite element method for solving fracture mechanics problem, were dealing with the complicated multilayer structures and strong non-linearity in human skin which make the computational model difficult to create and analyse. However, to overcome the difficulties with fracture mechanical part the Theoretical and Computational Aspects of Cohesive Zone Modelling has been adapted to make it suitable for( Frictional and Thermodynamically coupled Frictional) modelling of cutting and needle insertion by using a modified version of Contact-Fracture formulation (a specific implementation of a mesh independence method for straightforward controlling of (non-linear) fracture mechanical processes using Mixed Mode Cohesive-Zone method). To successfully deal with the problem or difficulty with the modelling of human skin for fracture mechanical analysis, because of its complexity, the problem has been subdivided into simpler problems and analysed.