A Validated Analytical Solution for the Two-Dimensional Bending of Aluminium Plates under Creep-Ageing Conditions

Abstract:

An analytical method suitable for modelling the creep-age forming (CAF) of doubly curved aluminium plates is presented. This new mechanics model combines an efficient numerical integration method with a robust set of CAF constitutive equations that has been experimentally validated with AA7055 at a CAF condition. Corresponding finite element simulations show good agreement with the analytical results. Using the validated analytical model to investigate a three-stage CAF process (loading, creep-ageing, and unloading), through-thickness strain distributions are studied for aluminium plates that have been subjected to different creep-ageing time. A creep activation point (CAP) is revealed and a correlation is found between the two parameters introduced in this work – the normalised location of CAP, zCAP and normalised bend ratio, β. More specifically, a linear relationship is found between β and zCAP, which indicates that the onset of creep strain, and hence the sizes of the pure elastic core and the outer creep region, can be readily predictable within the limits of study. It is now possible to simulate two-dimensional bending CAF processes for aluminium alloys that have non-spherical precipitates.

• Periodical: Key Engineering Materials (Volumes 622-623)
• Pages: 1107-1116
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.622-623.1107
• Online since: September 2014
• Authors: Aaron C. Lam*, Jian Guo Lin
• Keywords: Creep-Age Forming, Double Curvature Bending, Finite Element Analysis (FEA), Plate Bending, Residual Strains

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