Prediction of texture evolution under varying deformation states through crystal plasticity finite element method
(State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China)
Abstract: An explicit model controlled by a linear equations set was developed. This model was directly solved by the complete pivot GAUSSIAN elimination method without any iteration. In addition, crystallographic-system based solving procedure was proposed to reduce the additional calculation caused by grain rotation. By establishing crystal plasticity finite element model (CPFEM), the model was verified by comparing the predicted texture to the experimental results. Then, the model was applied to predict textures under different deformation states achieved by adjusting the ratio (k) of the loading velocities in Z and Y directions. The results show that the model is reliable in texture prediction (good agreement with the experiments in compression, tension, simple shear and plane-strain compression) and much more efficient (more than 100 times) than the implicit model; with the increasing of k, the strong texture progresses from ±35º to normal direction to fiber texture in the {111} plane and enhances in intensity; the texture intensity drops dramatically when the strain rate increases from 0.1 s-1 to 100 s-1, while drops slowly when the strain rate increases from 100 s-1 to 7×104 s-1, which indicates the computational stability of the model for simulation of ultra-high strain rate deformation.
Key words: crystal plasticity; texture evolution; deformation state; strain rate; explicit model