Damage analysis of Functionally Graded Materials under strong cyclic loading

Abstract

Monotonic or cyclic uni-axial loading tests on specimens with or without notch are designed to characterize the materials, and to develop in their results a formulation of the material either analytically or by prediction using a numerical technique, by the finite element method and using the ABAQUS calculation code, The novelty in this work lies in the way the notch itself is subjected to stress. Many studies have focused solely on damage to structures caused by the presence of notches, whereas in reality it’s the notches themselves that are subjected to sometimes severe and complex loading, The latter rapidly undermines the service life of these structures, strongly destabilizing the notch to the point of damage by a cyclic and uni-axial loading mode is the embodiment by a numerical prediction of this new idea in this work, which is based beforehand under simple condition on a validation of the numerical model to that of the experimental results, The fatigue behavior of the structure under the equivalent Von Mises flow stress is given by the combined hardening law, and the damage to the structure by crack initiation and propagation is also given by the XFEM (Extend Finite Element Method) technique, in the second part of this work, a reinforcement of the notch in the structure by a locally graded concept with another material surrounding the notch is proposed in order to delay damage under these loading conditions, the results of damage under the effect of the proposed parameters (grading concept and volume fraction index) have been highlighted in this work.