Coupling Between Mesoplasticity and Damage in High-cycle Fatigue

Abstract

ABSTRACT:The multiaxial fatigue loading in the high-cycle regime leads to localized mesoscopic plastic strain that occurs in some preferential directions of individual grains for most metallic materials. Crack initiation modeling is difficult in this fatigue regime because the scale where the mechanisms operate is not the engineering scale (macroscopic scale), and local plasticity and damage act simultaneously. This article describes a damage model based on the interaction between mesoplasticity and local damage for the infinite and the finite fatigue life regimes. Several salient effects are accounted for via a simple localization rule, which connects the macroscopic scale with the mesoscopic one, and by the model presented here, which describes the coupled effects of mesoplasticity and damage growth.Irreversible thermodynamics concepts with internal state variables are used to maintain a balance between extensive descriptions of plastic flow and damage events. Cyclic hardening behavior is described by a combined isotropic and kinematic hardening rule while the damage evolution is governed notably by the accumulated plastic mesoscopic strain. In this study, predictions are compared to fatigue tests performed on a mild steel (C36) under different loading modes. All the experiments are carried out under in-phase loading conditions: reversed tension, torsion, and combined tension-torsion. The mean stress effect is also studied through tests conducted under tension. The predicted Wo¨hler curves under any loading mode can be readily obtained with this model, but the main feature of this approach is to ensure a clear link between the mesoscopic parameters like the hardening behavior of individual grains and the subsequent local damage.

Fatigue life assessment of cardiovascular balloon-expandable stents: A two-scale plasticity–damage model approach

“…Different continuum damage mechanics based models have been proposed in the literature for the high-cycle fatigue analysis of metallic structures. Among others, models based on two-scale approaches in which micro and mesoscales are linked by means of a localization law (Lemaitre and Doghri, 1994;Lemaitre et al, 1999;Desmorat and Lemaitre, 2001;Lemaitre and Desmorat, 2005;Desmorat, 2006;Desmorat et al, 2007;Flaceliere et al, 2007aFlaceliere et al, , 2007b, and models relying on a single macroscopic (engineering) scale (Oller et al, 2005;Ottosen et al, 2008) can be found in the fatigue of metals literature. However, due to its inherent multi-scale manifestation, the high-cycle fatigue damage can only be properly captured by resorting to models which are capable of dealing with plasticity and damage on a scale smaller than the macroscopic scale, as for instance the two-scale models cited above.…”

A critical plane fatigue model with coupled meso‐plasticity and damage

“…This original critical plane model is derived from a previous approach based on a Von Mises type plasticity rule to model the fatigue behaviour of a group of average grains 21 …”

“…This original critical plane model is derived from a previous approach based on a Von Mises type plasticity rule to model the fatigue behaviour of a group of average grains. 21 The goal of the new model is to reflect the salient features of the mesoscopic behaviour of the crystal. The assumptions are:…”

Algorithms for multiaxial cycle counting method and fatigue life prediction based on the weight function critical plane under random loading

“…(2009)and Papuga (2011). Three categories of models are usually used: critical plane-based models (Carpinteri and Spagnoli, 2001; Carpinteri et al., 2003, 2014b; Papuga and Ruzicka, 2008; Shang et al., 2007; Shang and Wang, 1998; Susmel and Lazzarin, 2002; Zhang and Yao, 2011; Zhang et al., 2018), mesoscopic scale-based models (Brünig et al., 2011; Flaceliere et al., 2007; Eslami et al., 2016; Ju and Ko, 2008; Shariyat, 2010; Tay et al., 2008) and energy-based models (Ahmadzadeh and Varvani-Farahani, 2016; Chen et al., 1999; Zhu et al., 2012, 2017). Since the critical plane method has physical meaning, it is widely used in service.…”