非回转对称拉深中材料流动变形规律的研究

作为非回转对称拉深系统研究的一部分,根据矩形盒件拉深中网格变形的测量结果,分析了压料面和盒底面材料的流动变位及其规律。指出了凸缘周向压缩变形与径向拉伸变形不成比例,曲边部流动变形不连续,盒底面短轴上产生与拉深力作用方向相反的塑性流动等变形现象是与圆筒拉深变形的最大区别,同时也是非对称成形有限元计算试验所必须认识和掌握的基本关键点。试验表明,如果根据材料流动规律合理地实施规范化局部润滑,可使大型覆盖件拉深成形极限进一步提高。

ON THE LAW OF MATERIAL FLOW DEFORMATION IN A NONROTATIONAL SYMMETRICAL DRAWING

As a part of systematic study on non-rotational symmetrical drawing, flow displacement and law of materials of blank holder face and case bottom are analyzed according to the measurement of grid strain in rectangular case drawing. Comparing to strain in a cylinderic drawing, the greatest differences include: the compressive strain of circumferential direction in a flange is not proportional to its tensile strain of radial direction, and flow strain in a corner section is non-continuous, and the plastic flow opposite direction of drawing loaded is produced at a short axis of case bottom and other strain circum- stances. All these results are key points, which should be undersood and mastered, to do the calculation with the finite element method. Furthermore, these results also indicate that the forming limit of drawing for larger cover parts could be improved if local lubrication is suitably and reasonably carried out according to the law of materials flow.