摘要
钣金件多道次拉深中间构型的确定是塑性成形领域的一个难题。针对中间构型对多道次成形的影响,以轴对称盒形件为成形对象,采用试验方法进行了研究。试验设计了两种不同的中间构型,通过网格法研究在第1道次和第2道次中应变的分布规律;通过成形极限图研究两种中间构型第1道次和第2道次的成形性。试验结果表明,轴对称零件多道次成形在第2道次的成形中,底部成形近似为局部成形,容易在底部产生较大的拉伸应变,造成破裂缺陷,设计中间构型的底部应尽量与零件近似;第1道次和第2道次中沿母线方向的应变均为拉伸应变,自零件口部向零件底部周向的应变由压应变逐渐过渡到拉伸应变,以压应变为主,破裂一般发生在拉伸应变区。
In the field of plastic forming,it is difficult to determine intermediate shape of the blank in the multi-pass deep drawing of sheet metal.The experiment method was used to study the influence on forming of intermediate shape in multi-pass deep drawing forming of axis symmetrical workpiece.Two different intermediate shapes were used in multi-pass deep drawing forming.The strain distribution in first pass forming and second pass forming was studied by grid method.The formability of first and second pass forming for two intermediate shapes was researched by forming limit diagram.The results show that during the second pass forming of axis symmetrical workpiece,the forming in the bottom can be taken as local forming.It is easy to develop fracture in the bottom because of more tensile during forming.Therefore,the intermediate shape of the blank should be similar to final workpiece shape in the bottom in multi-pass deep drawing forming.The strain along the generating line direction is tensile strain in both the first and second pass of forming process.The strain along the circumferential direction is from compressive strain to tensile strain along the generating line from edge to bottom.The compressive strain is primary,and fracture appears in tensile strain area.
出处
《锻压技术》
CAS
CSCD
北大核心
2013年第4期27-32,共6页
Forging & Stamping Technology
基金
辽宁省教育厅基金资助项目(20090654)
关键词
多道次拉深
板料成形
中间构型
网格
multi-pass deep drawing
sheet metal forming
intermediate shape
grid
