Coupled experimental, finite element and nanotechnology-based investigation of process parameters in conical cup deep drawing

Abstract

Deep drawing is one of the most widely used sheet metal forming processes for manufacturing axisymmetric components with high dimensional accuracy and structural integrity. The quality of deep-drawn products is strongly influenced by process parameters such as blank holder force (BHF), punch speed, and tooling geometry, particularly when forming conical cups with inclined walls. In this study, a coupled experimental and finite element investigation was conducted to evaluate the influence of key process parameters on the forming load during the deep drawing of conical cups. Circular blanks of 1008 AISI low-carbon steel with a thickness of 0.9 mm and a diameter of 110 mm were employed. Deep drawing experiments were performed using a conical punch with a wall angle of 70° and a conical die and blank holder having an inclination angle of 12°. Three punch speeds (25, 75, and 125 mm/min) and three spring stiffness values corresponding to different blank holder forces (0.053, 0.066, and 0.072 kN/mm) were investigated. Finite element simulations were carried out using ABAQUS/Explicit 2021, where the punch, die, and blank holder were modeled as rigid bodies and the sheet blank as a deformable body. The numerical predictions were validated through direct comparison with experimental results. The results demonstrated that increasing the blank holder force increased the ultimate forming load due to higher contact pressure and friction at the flange region. The maximum forming load of 36.5 kN was obtained at a spring stiffness of 0.072 kN/mm and a drawing speed of 75 mm/min, whereas the minimum load of 33.36 kN occurred at 125 mm/min and 0.053 kN/mm. Good agreement was achieved between experimental and numerical results, confirming the capability of the finite element model to accurately predict the deep drawing behavior of conical cups and assist in process optimization. From a nanotechnology perspective, the study contributes to understanding deformation mechanisms occurring at micro- and nano-scales during sheet metal forming. The finite element model provides insights into localized strain distribution and surface integrity, which are critical for the manufacturing of advanced metallic components used in nanotechnology-enabled engineering systems. The findings demonstrate the potential of combining experimental measurements and numerical simulations for the optimization of precision forming processes required in micro-manufacturing and nano-engineered products.