Multi-field coupled analysis elucidating the impact of anisotropic magnetorheological elastomer-assisted free bending on wrinkling suppression and forming quality enhancement in thin-walled AA5A06 tubes

Abstract Thin-walled aluminum alloy tubes are prone to wrinkling during free-bending forming (FBF), which limits their forming limits and dimensional accuracy. This study proposes the use of anisotropic magnetorheological elastomers (α-MREs) as an intelligent internal support medium to actively suppress wrinkling. A comprehensive investigation was conducted on the free bending behavior of AA5A06 aluminum alloy tubes through a multi-field coupled methodology integrating theoretical analysis, finite element modelling (FEM), and experimental approaches. The theoretical analysis combining magnetic dipole theory with plastic mechanics was developed, and wrinkling prediction models based on the energy principle and thin-shell theory were established to determine the critical magnetic powder content, magnetic field strength, and minimum bending radius. α-MREs with different magnetic powder fractions were prepared and characterized, and an FBF platform incorporating an electromagnetic setup was built for experimental validation. A finite element model adopting the Mooney–Rivlin constitutive law was implemented to simulate the forming process. Results indicated that under optimal conditions of 30% magnetic powder content and a 225 mT magnetic field, the critical wrinkling bending radius was reduced by 20.9%, accompanied by a notable improvement in wall-thickness uniformity. Strong consistency was observed among theoretical predictions, numerical simulations, and experimental outcomes. This research provides an adaptive and intelligent strategy for high-precision, defect-free forming of thin-walled AA5A06 aluminum alloy components, contributing to the advancement of lightweight manufacturing technologies.