Bistable composite laminates: Effects of laminate composition on cured shape and response to thermal load

This paper develops a finite element (FE) approach using commercial ANSYS V11.0 software to accurately predict the cured shape of bistable composites by including the influence of manufacturing imperfections, such as resin rich areas and ply-thickness variations. Laminate composition was characterised by optical microscopy and their cured shapes measured using a Peak Motus motion analysis system. The FE model accurately predicts observed differences between laminate curvature in the two stable states. Localised reversal of curvature resulting from through-thickness shear stress is also predicted. Structural response to thermal loading was experimentally characterised showing a temperature dependent deflection rate and a residual curvature caused by non-reversible residual stresses. FE-predictions show good agreement with experiment over the range 20–110 °C. The presented data highlights the importance of manufacturing processes and materials selection in the design of thermally stressed multi-stable composite structures.