運用有限元素軟體模擬分析雙點漸進成形加工AA1050-O鋁板之回彈現象

Abstract

漸進成形加工是一種利用成形工具沿預設路徑移動，逐步使板材變形以製作所需工件的方法。此技術無需製作高成本模具，因此特別適用於小批量生產，有效實現產品客製化。儘管漸進成形具有高度加工自由度，然而精度控制與回彈預測仍是待解決的問題。 本研究採用有限元素分析軟體Abaqus，針對AA1050-O鋁合金板材在雙點漸進成形過程中的回彈行為進行分析。首先，透過反覆拉壓試驗了解板材的包辛格效應，並透過VUMAT子程式在Abaqus中實現了兩種降伏準則—Hill48與Barlat91，將其結果與Abaqus內建Hill48降伏模型的模擬結果及文獻中的實驗數據進行驗證和比較。另外，根據雙點漸進成形夾具中支撐模具的支撐完整性，做圓形部分模具跟方形部分模具的模擬與回彈分析。 從分析的結果可以知道，使用Barlat91降伏準則模擬時的輪廓較接近實驗的輪廓，可推論Barlat91降伏準則更適用於AA1050-O鋁合金板材的回彈分析。在使用方形部分模具模擬時，能有效降低回彈量。而Hill48降伏模型在VUMAT子程式與內建功能兩種實現方式下，回彈預測結果幾乎相同，證實採用VUMAT子程式的可行性與正確性。未來可以建立不同降伏準則（如Yld2000-2d、BBC2005）的材料模型，或是結合降伏準則與混合硬化模型以提升模擬準確性，以應用漸進成形在各種加工。

Incremental forming is a manufacturing process in which a forming tool gradually deforms a sheet metal along a predefined toolpath to produce the desired part geometry. This technique eliminates the need for costly dies, making it particularly suitable for small-scale production and enabling effective product customization. Despite its high forming flexibility, issues such as dimensional accuracy and springback prediction remain key challenges to be addressed. In this study, the springback of AA1050-O aluminum alloy sheet during Two Point Incremental Forming(TPIF) was analyzed using the finite element software Abaqus. The Bauschinger effect of the material was investigated through cyclic tension-compression tests. Two anisotropic yield criterion(Hill48 and Barlat91) were implemented via VUMAT subroutines in Abaqus. The simulated springback results were quantitatively evaluated and compared with both the built-in Hill48 model in Abaqus and experimental data from the literature. Additionally, this study explored the effect of support integrity by simulating two TPIF setups: one with a original partial die, and one with a fully supported partial die. The results showed that simulations using both yield criterion produced similar outcomes, with the Barlat91 model providing a better match to experimental contours. The simulated sidewall angles were also close to the ideal 65°, regardless of the yield model used. Moreover, the use of the fully supported partial die was found to effectively reduce springback. Finally, the springback predictions obtained from the VUMAT-implemented Hill48 model were nearly identical to those from the built-in Abaqus model, indicating minimal difference. Future work may involve developing material models incorporating other advanced yield criteria, such as Yld2000-2d or BBC2005, and coupling them with mixed hardening laws to enhance simulation accuracy for a wider range of incremental forming applications.