Bistable characteristics of hybrid composite laminates embedded with bimetallic strips

A novel bistable hybrid composite laminate embedded with bimetallic strips was designed by combining the stable-state characteristics of the bistable laminate with the temperature-sensing characteristics of the bimetallic strip described in this paper. A contactless method that deforms the bimetallic strip through the temperature field, driving the bistable laminate, is proposed. Firstly, an analytical method based on Dano's theory was developed to determine the principal curvature of the laminates, and qualitative and quantitative comparisons between theoretical, experimental, and numerical results were conducted and showed good agreement. Then, the influence of bimetallic strip characteristics such as the thickness, width, and material properties, along with the aspect ratio of the laminates, on the principal curvature were examined. In addition, the reciprocating drive of the laminates was realized by changing the temperature generated by a thermal field, and the effect of the bimetallic strip arrangement was also studied. Compared with the conventional square bistable cross-ply laminates, it was found that the new laminates have different curvatures in two stable states. In particular, they can be easily driven by changing the ambient temperature (contactless drive), without requiring complicated external driving devices. This study provides theoretical support and a new driving method for the design of adaptive and deployable structures.