Optimising process parameters and toolpath strategies for sheet metal flanging in incremental sheet forming

• Main Author: Kiera, Kathleen
• Other Authors: Paulo Jorge Da Silva Bartolo
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2024
• Subjects: Engineering; Incremental sheet forming; Hole flanging
• Online Access: https://hdl.handle.net/10356/181654
• Institution: Nanyang Technological University

This project investigates the influence of various processing parameters on the formability of hole flanging process using Incremental Sheet Forming (ISF) method. Parameters selected were tool diameter, tool shape, step size, feed rate, and toolpath strategy. Data collected included force data from the ISF robot, 3D scanning of the completed workpiece, and simulation work to supplement the findings. Results were analysed under 3 broad categories of fractural, geometrical, and surficial areas. Formability was optimised for tool diameter at a middle value of around 10-15mm. Experiments for tool shape showed hemispherical being beneficial over flat tool for all 3 areas. Increase in step size showed improvement in the fractural area however worsened surficial considerations. Increase in feed rate resulted in accelerated onset of fracture. Multi-stage toolpath strategy showed improvements across all 3 categories. Plot of force data generated by the robot against depth presented key features corresponding to the time position of the forming process. Force monitoring as a reflection of fracture occurrence was only possible under certain fracture conditions. Simulation work enhanced understanding of the stress-strain conditions experienced by the workpiece due to the forming process under certain selected sets of parameters. Future possible work includes varying blank size diameters in smaller increments, use of more simulation work and assisted ISF such as using heat or vibration.