Evaluation of Springback of AA5052-H36 Aluminium Alloy Sheet in Vee-bending

Springback (SB) is the partial elastic recovery experienced by the sheet metal upon removal of an applied load at the conclusion of the forming operation. SB is one of the causes of unsatisfactory bending since it results in loss of dimensional control in formed parts thus leading to problems that impacts quality and cost. In this work, the SB of aluminium (AA5052-H36) alloy sheet in vee bending is evaluated experimentally and with finite element analysis (FEA). Using ANOVA, this work investigates the relative effect of sheet metal thickness (2mm and 3mm), die opening (22mm, 35mm and 50mm) and punch holding time (0, 5 secs and 10 secs). SB modeling based on the forming parameters was conducted using multiple linear regression (MLR) and artificial neural network (ANN). This study showed that increasing values of the punch holding time and sheet thickness leads to reduction in SB while increasing die opening increases the SB for AA5052-H36 aluminium alloys, with the punch holding time having the most impact on SB. Parametric interactional effect between the punch holding time and die-opening showed significant impact on SB, while interactional effects involving the sheet thickness had insignificant impact on SB. ANN offered far superior SB prediction performance compared to MLR and FEA. In this work FEA simulation results demonstrate that increasing the die opening increases the SB while increasing the sheet thickness reduces the SB. This work demonstrates the formability of AA5052-H36 aluminuim alloy in cold work, where vee bends were performed with punch radius of 0.8mm and bend specimens showed no cracks, checking and surface roughness. Keywords: Springback, Finite Element Analysis, ANN, MLR.