Abstract:

For large forging internal defects, a multi-scale  simulation method was put forward,which was named as body cell model method. In the case of hole defects,the principles and applications of the body cell model method were discussed.Based on the body cell model method,the evolution behavior of hole defects in the particular forging was simulated. The evolution rule of hole defects and strain distribution around the hole defects were analyzed. And the lead block deformation experiments were carried out,which had  prefabricated artificial holes.The results show that holes gradually incline to closure with the increase of forging deformation degree, and the closure degree of holes is related to strain distribution in forgings.Results identical degree between physical experiments and numerical simulations are conceived is better. The simulation calculation of body cell model method is more accurate. Through the body cell model method, it is able to solve multi-scale calculation and analysis  of  internal defects in the forming process of large forgings.

Key words: large , forging;internal defect;trans-scale;body cell , model method

摘要：

针对大型锻件内部缺陷，提出了一种跨尺度模拟计算方法，即体胞模型法。以孔洞缺陷为例，论述了该方法的原理及应用思路。利用该方法对某锻件的孔洞缺陷演变行为进行了模拟计算，分析了孔洞缺陷的演变规律及其周围应变分布情况，并进行了人工预制孔洞的铅块变形实验。研究结果表明，孔洞随锻件变形程度增加而逐渐趋向闭合，其闭合程度与锻件应变分布情况有关；物理实验与数值模拟结果吻合度较高，体胞模型法的模拟计算较为准确;体胞模型法能够较好地解决大型锻件成形过程中内部缺陷的跨尺度数值模拟问题。

关键词: 大型锻件, 内部缺陷, 跨尺度, 体胞模型法