Investigation of the effect of U bending process parameters on the springback behavior

U bending is a widely used forming method for the production of metal parts in many industries. It is common to U-bend metal sheets in many applications such as furniture, vehicle parts, metal frames, door and window frames. Several strategies can be used to control springback during the U-bending process. These may include selection of appropriate forming parameters, material selection, heat treatment steps, stress relief and proper tool design. These methods can help to achieve more stable and accurate results by reducing the amount of springback. In this study, the effect of different material, sheet thickness and mould angle on springback in U bending process was investigated numerically and experimentally. In the experimental bending process, AISI 304 stainless steel sheets with 3 different sheet thicknesses (0.8, 1, 1.2 mm) and 3 different materials (AISI 304 stainless steel, DKP steel and Al 2014 aluminum) with 1 mm wall thickness were used. U bending operations were performed at 3 different mould radii and 4 different mould angles. As a result of U bending tests, it was observed that the springback amount decreased with increasing wall thickness of AISI 304 stainless steel sheets among 3 different materials, and the springback amount increased with increasing mould opening. In the same bending radius groups, springback values decreased as the bending angle increased. In Al 2014 sheets, springback decreased with increasing bending angle and springback increased with increasing mould radius. For DKP sheets, springback decreased with increasing mould angle and springback increased with increasing mould radius. In the U bending tests performed for 3 materials with the same wall thickness, it was observed that the least springback behaviour was obtained in DKP sheets.