Homogenized constitutive and fatigue nucleation models from crystal plasticity FE simulations of Ti alloys, Part 2: Macroscopic probabilistic crack nucleation model
Homogenized constitutive and fatigue nucleation models from crystal plasticity FE simulations of Ti alloys, Part 2: Macroscopic probabilistic crack nucleation model
复制标题
DOI：
10.1016/j.ijplas.2013.02.008
复制
发表时间：
2013-09
影响因子：
9.8
通讯作者：
M. Anahid;Somnath Ghosh
中科院分区：
文献类型：
--
作者：
M. Anahid;Somnath Ghosh
这是一篇由两部分组成的论文的第二部分，旨在发展多晶钛合金疲劳变形和破坏的宏观模型。在这一部分中，建立了一个概率裂纹形核模型，用于从严格的微观分析出发，在结构构件的宏观计算中预测损伤形核。该模型的输入包括任意材料点处微观组织的形态特征以及局部应力/应变状态。触发该模型所需的应力状态可以通过使用在第1部分中开发的均化各向异性塑性本构(HAPC)模型的有限元分析来获得(Ghosh等人，在出版社中)。通过对实现了基于物理的晶级裂纹形核模型的双晶系代表性体积元的严格晶体塑性有限元模拟，得到了一个确定的函数形式，将宏观裂纹形核时间与宏观应力状态和微观结构特征参数联系起来。随后，根据该函数形式生成了宏观(结构)尺度上的预期裂纹形核的概率模型。该概率模型与微结构裂纹形核机制有直接联系，可通过宏观有限元分析结合局部微观组织的统计知识得到。
This is the second of a two-part paper aimed at the developing macroscopic models of fatigue deformation and failure in polycrystalline Ti alloys. In this part, a probabilistic crack nucleation model is developed for predicting damage nucleation in macroscopic computations of the structural components from rigorous microscopic analyzes. Inputs to this model include morphological characteristics of the microstructure at any material point along with the local stress/strain state. This stress-state, needed to trigger this model, can be obtained from finite element analysis using the homogenized, anisotropic plasticity constitutive (HAPC) model developed in part 1 (Ghosh et al., in press). A deterministic functional form, relating time for macroscopic crack nucleation to the macroscopic stress state and microstructural characteristic parameters, is derived from rigorous crystal plasticity FE simulations of representative volume element of a bi-crystal system that implements a physics-based grain level crack nucleation model. Subsequently, a probabilistic model for expected crack nucleation in the macroscopic (structural) scale is generated from this functional form. The probabilistic model has a direct connection to the mechanisms of microstructural crack nucleation and can be obtained from macroscopic FE analysis with knowledge of statistics of the local microstructure.