本文採用動顯函有限元素法結合更新的拉格朗日式之虛功率原理，進行微方杯凸緣製程之分析，探討不同沖頭底部圓弧角半徑與不同料片直徑對成形極限、沖頭負荷與衝程關係、von Mises應力分佈、等效塑性應變分佈，及厚度分佈之影響。 本文設計三組沖頭與一組沖模進行微方杯凸緣分析，當料片直徑相同時，工件達成形極限之沖頭衝程隨著沖頭底部圓弧角半徑增加而遞增；當沖頭底部圓弧角半徑固定時，工件達成形極限之沖頭衝程則隨著料片直徑增加而遞減。然而，當沖頭衝程固定，並採用相同直徑之料片時，沖頭負荷將隨著沖頭底部圓弧角半徑增加而遞減；當沖頭底部圓弧角半徑固定時，沖頭負荷將隨著初始料片直徑的增加而遞增。經由數值分析與實驗結果之比較得知，本文之動顯函有限元素分析程式可合理預測微方杯凸緣成形製程。 The dynamic-explicit finite element method based on the virtual power theory of the updated Lagrangian formulation was developed to analyze the flanging process of micro square cup. The forming limit, the relationship between punch load and punch stroke, the distribution of von Mises stress, effective plastic strain, and thickness were discussed and compared with experimental results for various arc radii of punches and various diameters of blanks. This study designed three sets of punch and one set of die to analyze the flanging process of micro square cup. When the diameters of blanks were identical, the punch stroke of workpiece in forming limit would increase with an increase of arc radius of punch. When the arc radius of punch was fixed, the punch stroke of workpiece in forming limit decreased with an increase of the diameter of blank. However, the punch load would decrease with an increase of arc radius of punch, when the punch stroke was fixed and the identical diameter of blank was used. When the arc radius of punch was fixed, the punch load increased with an increase of the diameter of blank. By comparison of numerical and experimental results, it showed that the dynamic-explicit finite element analysis method could be used to predict the flanging process of micro square cup reasonably.
