薄板件台阶孔冲压冷锻组合工艺的数值模拟

针对构想的一种薄板件台阶孔冲压冷锻组合工艺，应用金属塑性加工有限元模拟的关键技术，包括几何模型、材料断裂破坏、网格划分等，用DEFORM-3D软件对此种薄板件台阶孔的冲压冷锻组合变形进行数值模拟。得到了工件材料的等效应力、应变分布，速度场和力—行程曲线。提出细观变形过程可分为冲头小直径处冲孔、冲头大直径处压凹和闭式模锻三个阶段的认识，分析组合工艺特点和材料成形性能。用料厚为2.35 mm的AL-1100铝板材料进行工艺试验，获得了清晰的台阶孔形状，验证了数值模拟的认识。

Numerical Simulation of Flow Control Forming Process for Stepped Hole of Thin Sheet Metal

Aiming at a previously conceived combined process of stamping & cold forging for stepped hole of thin sheet metal, by using DEFORM-3D software, numerical simulation of the deformation of this combined process is carried out by use of key technologies of finite element simulation for metal plastic working which includes geometrical model, material fracture damage and meshing technology, etc. Distributions of effective strain and effective stress, velocity field and force-stroke curve are obtained. A conclusion is drawn that the minute deformation can be divided into 3 stages, including punching with punch small-diameter side, concaving with punch big-diameter side and closed die forging. The technological features of this combined process and the material forming performance are analyzed. Technological experiments using AL-1100 sheet with a material thickness of 2.35 mm are carried out and clear profile of stepped hole is obtained, which verifies the above conclusion.