Description:
Double curvature nacelle skin components are often produced in 2024-T3 Alcladaluminium alloy (clad both sides), using simple stretch forming. For this process uniaxial-tension isassumed to be the dominant mode of deformation. The observed springback in these components isgenerally minimized by inducing high levels of strain within the forming limits of the material.Experimental investigations to quantify the level of the springback have revealed an underlyingaspect of material behaviour, which to the authors’ knowledge, has not been reported elsewhere.The results of this investigation have shown a remarkable dependence on specific materialparameters unique to the Alclad material. Whilst previous investigations [1, 2, 3] have shown theinfluence of cladding, it has been assumed that cladding layers on both sides produce effects that aresymmetrical about the mid-plane of the sheet. However, the current investigation has revealed adistinct asymmetry in springback behaviour. A detailed study of cladding thickness and strength,residual stresses and through-thickness material property changes has revealed that this asymmetryresults from a complex combination of these parameters.