Multistable characteristics of cruciform unsymmetric composite laminates with notch design

This paper proposes a novel cruciform multistable composite laminate achieved by cross-laying two unsymmetric rectangular laminates and introducing a notch design. The notch design resolves the issue of large stiffness within the co-curing area of laminates resulting from co-curing process. A finite element model of the cruciform multistable composite laminate was established, and specimens were fabricated by autoclave process. The feasibility of the notch design was validated through simulation and experimental results. In addition, the effects of the co-curing area, notch angle and rectangular aspect ratio on the stable configurations of the cruciform multistable laminates were further investigated. The result shows that the co-curing area demonstrates a linear relationship with the maximum out-of-plane displacement of configuration Ⅰ. The notch angle significantly impacts Configuration Ⅱ, whereas the aspect ratio of the laminate plays a crucial role in Configuration Ⅰ.