Eventos Anais de eventos
MecSol 2017
6th International Symposium on Solid Mechanics
NON SATURATING KINEMATIC HARDENING LAW COUPLED WITH DAMAGE EVOLUTION FOR FATIGUE
Submission Author:
Rodrigue Desmorat , Ile de Frace , France
Co-Authors:
Estarle Roberto Ferreira de Souza Campos, Lucival Malcher
Presenter: Estarle Roberto Ferreira de Souza Campos
doi://10.26678/ABCM.MecSol2017.MSL17-0142
Abstract
Abstract: The present contribution proposes the use of an advanced plasticity model coupled to the improved continuum damage model in order to estimate low cycle fatigue life under proportional and non-proportional loading conditions. The plasticity model is based on a non-linear and non-saturating power law for the kinematic hardening modeling, proposed by Desmorat (2010) and Prisacari et al (2016). This model describes the non symmetry of the hysteresis loops and captures the effect of partial mean stress relaxation. For a better description of multiaxial fatigue – than by the original Continuum Damage Mechanics (CDM) approach of Lemaitre type – a modified microcracks closure effect is derived and introduced in the damage evolution law (Malcher & Mamiya, 2012). Here we represent the microcraks closure effect by a “hydrostatic sensitivity to damage”, keeping the relation between the deviatoric stress and damage unaltered. The improvement consists in substituting the damage strength, constant material parameter S in initial Lemaitre law, by a function, dependent on both stress triaxiality and normalized third invariant. An implicit numerical integration scheme is suggested and implemented. Numerical results are compared with experimental data available in literature and parameters governing partial mean stress relaxation, evolution of damage/stress/strain variable and fields as well as fatigue life, are analyzed.
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