Mechanical Properties Analysis and Optimization Design for Bistable Hybrid Composite Shells

A type of bistable hybrid shell composed of metallic materials and composites was proposed to improve the load-bearing capacity of bistable structures. The mechanical properties in the transition process between two stable states were investigated based on the numerical simulation method. The effects of metal thickness, ply angle, radius and length of bistable hybrid shell on the load-bearing capacity and the configuration of the second stable state were discussed. The primary and secondary sequence method was employed to investigate the relative importance of the geometric parameters on the mechanical properties. The optimization model was established based on the response surface methodology (RSM), where the design variables were the geometric parameters, the constraint was the allowable stress and the objective was to maximize the snap load. The sequential quadratic programing algorithm was adopted to solve the optimization model, and the optimal designs were obtained. The proposed method has a great of significance in improving the mechanical properties for bistable structures.