A crystal plasticity model that accounts for grain size effects and slip system interactions on the deformation of austenitic stainless steels
A crystal plasticity model that accounts for grain size effects and slip system interactions on the deformation of austenitic stainless steels
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DOI：
10.1016/j.ijplas.2022.103249
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发表时间：
2022-02-16
影响因子：
9.8
通讯作者：
Knowles, David
中科院分区：
文献类型：
--
作者：
Agius, Dylan;Kareer, Anna;Knowles, David
为了确保更有代表性的模拟中尺度和宏观尺度的变形，重要的是，潜在的本构关系是先进的，以更有效地纳入微观机制，如那些在晶界附近的操作。准确预测所需的关键特征包括晶粒尺寸、形态和取向差对局部变形的影响。在这项研究中，一个长度尺度的依赖被纳入经典的晶体塑性模拟。该方法基于Hall-Petch理论，利用位错滑移在晶界处堆积的影响，对材料进行了数值模拟。这是通过应用专门构建的算法来提取沿沿着每个滑移方向的相邻晶粒中的滑移距离来实现的。该提取的数据用于调整晶粒内的临界解析剪切应力。然后将调整后的滑移律应用到本构模型中，预测不同晶粒尺寸下材料的屈服应力和硬化演化。同时考虑了晶粒间滑移系的相互作用，从而根据取向差调整了晶粒间滑移传递的程度。所提出的方法可以应用于有限元和谱方法求解连续微分方程。通过考虑使用二维模拟的中尺度预测，以及使用三维模型的宏观尺度预测，研究了所提出的模型的准确性。此外，该方法的有效性实验支持通过跟踪晶内残余弹性应力的发展，通过高分辨率电子背散射衍射测量。讨论的结果突出了一个新的潜力，提高复杂的晶界相互作用的方式，有助于在晶体塑性模拟的局部变形。
To ensure a more representative simulation of meso-scale and macro-scale deformation, it is important the underlying constitutive relations are advanced to more effectively incorporate the micro-mechanisms such as those operative near the grain boundaries. Critical features necessary for accurate predictions include the influence of grain size, morphology, and misorientation on the local deformation. In this study, a length scale dependence is incorporated into classical crystal plasticity simulations. The implementation is based on the influence of dislocation slip pile-up at grain boundaries based on the Hall-Petch theory in materials. This was achieved by applying a purpose-built algorithm to extract the slip distance in adjacent grains along each slip direction. This extracted data was used to adjust the critical resolved shear stress within the grain. The adjusted slip law was then implemented in constitutive models to predict the yield stress and hardening evolution of material for different grain sizes. The interaction of the slip systems between grains was also considered, which resulted in the adjustment in the extent of slip transfer permitted between grains based on misorientation. The proposed approach can be applied in both finite element and spectral methods for solving the continuum differential equations. The accuracy of the proposed model was investigated by considering the meso-scale predictions using twodimensional simulations, in addition to macro-scale predictions using three-dimensional models. Furthermore, the validity of the method was experimentally supported by tracking the development of intragranular residual elastic stresses, measured via high-resolution electron back scatter diffraction. The discussed results highlight a new potential of enhancing the way in which complex grain boundary interactions contribute to local deformation in crystal plasticity simulations.