Author(s)

E Ballatore

Abstract

Influence of localised damage around crack tip on fracture propagation E Ballatore Department of Structural Engineering, Politecnico of Torino, Italy Abstract The Author, in previous researches, has defined a model for evaluation of Mixed Mode crack propagation, considering the mechanical damage effects. According to this model, a computer program, using a composite finite element named octagonal core with singular radial nodes, has been developed and tested comparing numerical simulations with experimental results. This paper describes an application of the numerical code in order to analyse the localisation of damage around the crack tip for Mode I and Mixed Mode problems. The results of numerical simulations show that the strain-rate has a greater influence on damage distribution than on crack extension. 1 Introduction The damage crack model can describe the fracture behaviour under loading and slow crack growth in Mixed Mode problems. The crack growth depends on the strain energy density and on mechanical damage of the material around the crack tip. The material damage is assumed to be related to the strain and stress fields. The finite element computer code, named SFEA, and developed by Author, has been designed for applying the damage crack model with an evolutive analysis technique that allows a complete simulation until final collapse. The code has been tested comparing numerical simulations with experimental results, as reported in [1,2]. The numerical simulation results are strain-rate dependants; for

Keywords