HILL屈服准则与晶体塑性模型对FCC单晶材料塑性各向异性描述能力的比较

Comparative study of Hill model with crystal plasticity for FCC single crystals

采用宏观 HILL 模型和晶体塑性模型对面心立方单晶 ( FCC)材料的非均匀变形进行了数值模拟 ,意在比较两种不同尺度的模型对塑性各向异性的描述能力的差异。为了使两种模型具有可比性 ,对于 FCC单晶材料 ,本文提出一种用晶体塑性模型来确定 HILL模型中各向异性参数的标定方法。数值分析表明 ,两类模型对单晶体塑性各向异性的描述能力存在着差异。对 FCC单晶材料 ,HILL模型对各向异性的预测能力没有晶体塑性模型细致 ,晶体塑性模型更能追踪塑性各向异性的变化。但两种模型对应力应变响应预测的趋势是一致的。对两种模型描述的差异 。

An inhomogenous deformation process is analyzed by application of a macroscopic Hill model and crystal plasticity. The purpose of present work is to give a comparative study of the different description ability of these two different-scale models on plastic anisotropy. The material parameter values for the macroscopic model are chosen so that the predictions of the two models can be close with each other. Numerical simulations show that the two models give some difference prediction of plastic anisotropy. For FCC single crystals, the crystal model gives more particular description than that of Hill model. The interpretations for such differences are analyzed in detail.