Cured Shapes of Bi-stable CFRP Composite Laminates with the Side Length Exceeding a Critical Value

Abstract

Curvature saturation has been observed in bi-stable composite laminates when the side length exceeds a critical value. This is the curvature which the stable cylindrical shell converges to after cooling down. Conventional models of the displacement field fail to predict the correct shapes. This is especially true when the laminate forms a wound-up cylinder which can occur when the longer side is several times the critical length. This paper presents a saturated curvature model to predict the cured shape for bi-stable laminates. The finite element analysis is also carried out to capture the cured shape. Both the analytical model and finite element method give the accurate cured shape. The cured shapes are measured experimentally. The results from the proposed model and finite element analysis are compared with the experimental and show a good agreement.