基于宏、细观模型的疏松缺陷研究方法

疏松缺陷在钢锭凝固过程中的形变能力影响了镦粗工件的最终性能，为消除锻造过程中的疏松缺陷，研究其闭合规律，需要建立正确的有限元模型。本文利用有限元分析软件Deform-2D建立宏细观两种尺度下的模型进行数值模拟，细观尺度下的模型为含有疏松缺陷的代表性特征体积元（RVE），从宏观模型中抽取适当边界条件加载到代表性特征体积元（RVE）上，从而保证从宏观模型到细观模型数据传递的准确性，使细观模型能够再现宏观模型中存在疏松缺陷单元的热锻闭合过程，得到了传统有限元方法不易得到的良好效果，对合理制定锻压工艺从而消除锻件内部缺陷提供了重要理论依据。

Research Methods of the Loose Defects Based on the Macro and Meso Models

The deformation ability of the loose defects in the ingot solidification process affects the final properties of the upsetting workpiece.To eliminate the loose defects in the process of the forging and obtain the closed rules of the loose defects,it is necessary to establish the correct finite element model.In this paper,the finite element analysis software,the Deform-2D,is used to build the macroscopic and mesoscopic models of the two scales.The meso-scale model is the representative volume element(RVE)which contains the loose defects.To extract the appropriate boundary loading conditions from the macro model and load into the RVE,it is able to ensure the accuracy of the data transferring from the macro model to the microscopic model.Thus it can reproduce the closed process of the elements which exist the loose defects in the macroscopic model during the hot forging process.From above we can get the ideal results not easy to get from the traditional finite element methods,which can also provide us with the important theoretical basis for establishing a reasonable forging process and eliminating internal defects of the forgings.