辊式微楔横轧数理建模及仿真分析

Mathematical modeling and simulation analysis of roll micro cross wedge rolling

在微楔横轧技术的理论研究阶段,准确的细观有限元模型和多晶体塑性模型的结合可以更好地优化其成形工艺。首先采用三维Voronoi多面体来研究真实材料的细观结构,建立了基于Voronoi原理的光滑模型和粗糙模型,然后单独对每一个晶粒考虑塑性性能和初始取向,建立了两种多晶体塑性模型,最后将光滑/粗糙Voronoi几何模型和经验模型相结合,建立了成形微型轴辊式微楔横轧有限元分析模型。利用ABAQUS软件进行仿真模拟,通过分析不同因素对工件成形质量的影响,得到在MCRW中要使工件成形质量最佳应选择粗糙模型、网格尺寸0.03 mm、摩擦系数0.8以及工件中晶粒数量82个。

In the theoretical research stage of micro cross wedge rolling technology（ MCWR）,the combination of accurate finite element model and multi crystal plasticity model can optimize the forming process of MCWR. Firstly,the three-dimensional Voronoi polyhedron was used to study the microscopic structure of the real material and a smooth model and a rough model based on the principle of Voronoi were established. Then the plastic properties and the initial orientation were considered separately for each grain and two kinds of polycrystalline plastic models were established. Finally,the finite element analysis model of micro roll forming MCWR was established by combining the smooth/rough Voronoi geometric model with the empirical model. After analyzing the influence of different factors on forming quality of workpiece by using ABAQUS for simulation,it is found that in MCRW,the rough model,mesh size of 0. 03 mm,friction coefficient of 0. 8 and the grain number of 82 in workpiece should be chosen to make the workpiece forming quality the best.