一种预测左半部成形极限图的简单方法

板材成形性能的评价一般基于成形极限图(FLD)。然而，无论是经由理论计算还是实验方法来获得成形极限图依然很困难而且很耗时。提出了一种预测深拉延部分成形极限图的新方法。假设对所有钢板来说其成形极限图的形状几乎都是一样的，而深拉延变形区域内其失效厚度应变也几乎一样，据此可利用体积不变原理推导出主应变和次应变之间的关系。结果表明，根据此方法计算的左半侧(拉深应变区)成形极限图与实验获得的FLD基本一致。

Approach for Predicting the Limit Draw Strain of the Forming Diagram

This paper proposed a new approach for predicting the limit draw strain of the FLD.It is assumed that the shape of the forming limit diagram is approximately constant for all steels,and failure thickness strain is approximately the same for draw deformation. So the correlation between the major strain and the minor strain can be derived using the constant volume equation.The calculation FLDS of the draw strain side show good agreement with experiment FLDS.