Al3105/polypropylene/Al3105 laminates springback in V-die bending

Metal/polymer/metal laminated sheets have shown promising properties, as being light weight, in automotive and aircraft industries. In this paper, the effect of punch radius on springback in the early stage of V-die bending process of aluminum/polypropylene/aluminum sheets is studied both numerically and experimentally. To analyze springback behavior, contact pressure evolution during bending process was studied using numerical simulation. Springback behavior relies on bending moment and sheet thinning. Bending moment and sheet thinning depend on circumferential and transverse stress distributions along sheet thickness and sheet length. Overall opposite effect of bending moment and sheet thinning makes an increase in springback with punch radius. Parametric study was performed to investigate the effect of polymeric core on springback. It was observed that in a given thickness configuration, springback of laminate lies between those of polymeric and metallic monolayer sheets with the same thickness. Also, an increase in sandwich sheet thickness leads to a decrease in springback.