Experimental Study of Sheet Incremental Forming Process with Controlled Movement of Material into the Forming Cavity

Incremental forming is one of the methods for single-piece forming of metal sheets. In the conventional configuration of this process, the sheet is held fixed between holders, preventing any movement toward the forming cavity. Since the presence of draw beads in deep drawing dies controls the material flow into the die, thereby reducing defects such as wrinkling and thinning, this study incorporates this feature into the design of the holders in sheet incremental forming. Experimental tests were conducted both with and without the bead, and the effect of its presence on sheet thickness variation and forming accuracy was evaluated. In this context, with a different definition of the bead performance, its positive role in the incremental forming process is also noticeable, with the distinction that the blank holder’s role is to control the contact surface between the sheet and the holders and to regulate friction. Experimental observations confirm that in the case of linear contact between the holders and the workpiece through a double bead, controlled movement of the sheet into the cavity is possible, which in turn reduces thinning by approximately ۳۰% while maintaining forming accuracy.

کلیدواژه ها:

Incremental Forming ، Sheet metal forming ، Draw bead