Slip Systems and Initiation of Plasticity in a Body-Centered-Cubic Titanium Alloy
Slip Systems and Initiation of Plasticity in a Body-Centered-Cubic Titanium Alloy
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DOI：
10.1007/s11661-010-0284-5
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发表时间：
2010-10-01
影响因子：
2.8
通讯作者：
Geltmacher, Andrew B.
中科院分区：
文献类型：
--
作者：
Lewis, Alexis C.;Qidwai, Siddiq M.;Geltmacher, Andrew B.
为了确定三维（3-D）微观结构中统计相关的微观结构-屈服相关性，必须研究由许多晶粒组成的大体积。为了限制计算载荷而不降低被模拟的体积的保真度，这项工作研究了使用减少的本构参数，特别是可用的滑移系的数量，分析初始塑性流动的微观结构。这是通过在有限元（FE）计算模型中嵌入单相β-Ti微结构的3-D重建并使其经受许多载荷条件来执行的。三种单独的单晶塑性制剂用于每种负载：减少12个滑移系统（aOE（c）111 >{110}族），减少24个滑移系统（aOE（c）111 >{110} + aOE（c）111 >{112}族），和全部48个滑移系统（aOE（c）111 >{110} + aOE（c）111 >{112} + aOE（c）111 >{123}族）。分析结果表明，24滑移系统模型准确地预测了全球的应力-应变行为和位置的初始屈服在所有负载下，与不超过10%的误差在空间描述的局部状态变量相比，完整的48滑移系统模型。12滑差系统模型一般遵循完整的模型预测，并提供了一个更好的成本改善，但在当地的描述超过40%的误差。计算成本和数据减少分别提高了26%和53%。
To determine statistically relevant microstructure-yield correlations in three-dimensional (3-D) microstructures, large volumes comprised of many grains must be studied. With the aim of limiting computational loads without reducing the fidelity of the volume being simulated, this work investigates the use of reduced constitutive parameters, specifically the number of available slip systems, to analyze initial plastic flow in the microstructure. This is performed by embedding a 3-D reconstruction of a single-phase beta-Ti microstructure in a finite element (FE) computational model and subjecting it to a number of loading conditions. Three separate single-crystal plasticity formulations were used for each loading: reduced 12 slip systems (aOE (c) 111 >{110} family), reduced 24 slip systems (aOE (c) 111 >{110} + aOE (c) 111 >{112} families), and full 48 slip systems (aOE (c) 111 >{110} + aOE (c) 111 >{112} + aOE (c) 111 >{123} families). The analysis results show that the 24-slip-system model accurately predicts the global stress-strain behavior and locations of initial yield under all loadings, with no more than 10 pct error in the spatial description of local state variables compared to the full 48-slip-system model. The 12-slip-system model generally follows the full model predictions and provides an even better cost improvement, but with errors in excess of 40 pct in local descriptions. Computational cost and data reduction are improved by 26 and 53 pct, respectively.