摘要
The stretch flanging process is significantly affected by various geometrical,material and process parameters.The punch-die clearance and initial flange length are main parameters which have major effects on the edge crack location and strain distribution along die profile radius in the flange.Non-axisymmetric stretch flanging process of AA-5052 sheet metal blanks was carried out by numerical simulation to predict the deformation behavior of flange,location and propagation of crack in flange and to investigate the effect of punch die clearance,flange length,die and punch profile radius and friction in the stretch flanging process.The experimental investigations were made to validate the simulations results.The results reveal that the crack length increases with the increase in the flange length.It is found that the flange length has a significant effect in circumferential direction as compared with the radial direction.The punch die clearance has the most significant effect in crack propagation in comparison with flange length.The circumferential strain is found to be larger in the case of punch having the profile radius less than the die profile radius,which leads to faster edge crack propagation.A close agreement is found between simulation and experimental results in terms of location of edge crack and forming load.
拉伸翻边工艺受多种几何形状、材料和工艺参数的影响。冲模间隙和初始翻边长度是影响边界裂纹位置和沿模侧面半径应力分布的主要参数。采用数值模拟研究AA-5052铝板的非轴对称拉伸翻边工艺,预测翻边的变形行为、裂纹位置和扩展,并且研究拉伸翻边过程中冲模间隙、翻边长度、冲模外形半径和摩擦力的影响。利用实验研究对模拟结果进行验证。结果表明,裂纹长度随翻边长度的增加而增加,翻边长度在周向的影响比在轴向的影响大,冲模间隙比翻边长度对裂纹扩展的影响更大。当冲孔外形半径比模的外形半径小时,周向应变增加,这导致了较快的边裂纹扩展。在边裂纹位置和变形负载方面,模拟结果和实验结果较好吻合。
基金
the Science and Engineering Research Board(SERB)
Department of Science & Technology,Government of India for financially supporting this research
