Evaluation of Strain Distribution of Perforated Sheet in Circular Cup Deep Drawing

Perforated metal sheets with numerous holes created by punching are used for various purposes, ranging from automotive parts to daily kitchen products, in applications such as ventilation, soundproofing, shielding from sound and light, and weight reduction. However, the plastic forming of thin metal sheets has generally been limited to materials of uniform thickness and quality. It has not been the subject of significant technological development or research. Most current products have flat shapes or are simply bent, and there are few precedents for machining methods that apply strong forces to the hole edges. In the drawing process, in which a strong force is applied to the hole edge, changes in tensile and compressive deformation occur due to discontinuities in deformation resistance. This results in non-uniform sheet thickness caused by a combination of deformation in the holes and no deformation in the surrounding sheet. Therefore, clarifying the drawing characteristics of perforated sheets will contribute to progress in plastic forming.