Title : Development of advanced robotic incremental sheet metal forming processes
Abstract:
Rapid prototyping has become increasingly indispensable in the iterative development of novel products across a spectrum of industries, including aerospace, automotive, construction, and biomedical sectors. Besides the prevalent 3D additive manufacturing technologies, robotic incremental sheet forming processes have emerged as versatile tools for fabricating customized and small-batch products, offering inherent advantages in flexibility, efficiency, and cost-effectiveness. This versatility is particularly pronounced when addressing the intricate requirements of large-sized sheet metal components. One persistent challenge encountered in incremental sheet forming process is the emergence of pillow defect at the sheet centre, a phenomenon known to compromise the formability of components and elevate the forming load. In response, this research systematically explores the impact of various factors, such as bend severity, forming wall angle, forming strategy, tool shape, and stepdown size, on the occurrence of the pillow defect during the incremental sheet forming process. Notably, the investigation culminates in the successful formation of a complex trihedral component devoid of the pillow defect through incremental sheet forming technology. However, the conventional incremental sheet forming process proves impractical when applied to the shaping of thicker and stronger parts, primarily due to the increasing forming loads involved. In response to this limitation, the research introduces an innovative ultrasonic-based double-side incremental sheet forming process, demonstrating a significant reduction in forming load accompanied by an impressive enhancement in geometric accuracy. The findings reveal a remarkable 56% reduction in the maximum average forming force and a noteworthy 72% improvement in surface accuracy. By advancing our understanding of the intricate mechanisms underlying the formation of the pillow defect in metal sheets, this research not only contributes to the scientific understanding of incremental sheet forming but also propels the frontiers of ultrasonic-based double-side incremental forming technology. This development holds promise for future applications, particularly in the realm of efficient, cost-effective, and precise manufacturing processes for complex sheet metal components.
