Effect Of Variation in Elastic Properties On Springback in Aluminium Sheet Metal Forming: A Parametric Finite Element Study With Four Drawbead Geometries

Abstract

Springback is a recurring issue for dimensional accuracy in sheet metal forming process. This study presents a efficient parametric finite element (FE) investigation of the effect of Young’s modulus variation (E = 60, 65, 71, and 75 GPa) on springback angle in AA 6061-T6 aluminium sheet (300 × 45.86 × 1 mm, yield strength σy = 276 MPa) forming with a 90° V-block die and R10 mm punch, across four drawbead configurations: no drawbead (SM N), circular (SM C, inner R1/outer R2 mm), triangular (SM T, 2 × 2 mm), and square (SM SQ, 2 × 2 mm, R0.2 fillet). Simulations were performed in ANSYS Static Structural 2022 R1 using a bilinear isotropic hardening model. Springback angles were measured in ANSYS SpaceClaim from STL geometry exports at solver time t = 60 s (fully loaded) and t = 120 s (fully unloaded), with ±0.5° measurement uncertainty. Three principal findings are reported. First, springback decreases with increasing E for SM C (R2 = 0.90, slope = −0.206°/GPa) and SM T (R2 = 0.99, slope = −0.269°/GPa). Secondly, square drawbead restricts springback to below 0.8° independant to E values, due to a novel drawbead bending severity index (SM SQ = 3.333; 5× higher than SM C) derived from confirmed engineering drawing dimensions. Thirdly, springback from FE factors agree with the Kalpakjian analytical model within 5% for SM N, SM C, and SM T, validating the simulation. An elastic strain energy density analysis (U = σ2/2E) provides a novel energy-based mechanistic explanation of the results. Ten publication-quality figures and five data tables provide a complete, reproducible dataset. Findings provide quantitative guidance on drawbead selection and material property utilisation in aluminium forming processes.