Hydro-mechanical deep drawing of conical components: Wrinkling behavior and process enhancement

This study explores the hydro-mechanical deep drawing process of a conical part through finite element simulations using ABAQUS software. The central focus is on investigating the occurrence of wrinkling during the forming process. Given the limitations in generalizing previous studies on wrinkling, there is a critical necessity to comprehensively comprehend and mitigate wrinkling behavior through an investigation into the interplay of various parameters. In response to the recognized challenge of minimizing wrinkles, an experimental setup with a hydro-mechanical deep drawing die was resented, aiming to validate and refine the simulation results. Additionally, a comprehensive study is conducted regarding the effect of fluid pressure, chamber pressure, pre-bulge height, friction coefficients, and sheet thickness on wrinkling behavior. The findings reveal that, at a pre-bulge pressure of 40 bar and a pre-bulge height of 2 mm, the minimum wrinkling height is observed to be merely 0.02 mm — the lowest recorded value. Notably, an increasing drawing ratio demands a 50% higher minimum chamber pressure to prevent wrinkling in the flange. Furthermore, a larger distance between the sheet and the die reduces the safe working range by approximately 57%, impacting the production of a wrinkle-free part. Conversely, elevating the pre-bulge pressure results in a 50% expansion in the safe working area for producing a wrinkle-free part. By explicitly stating the challenge of minimizing wrinkles, this study aims to contribute valuable insights into optimizing the hydro-mechanical deep drawing process for enhanced efficiency and improved product quality.