Snap-through behavior of bistable beam with variable sections: mechanical model and experimental study

Abstract

Bistable and multistable structures with snap-through behavior can achieve nonlinear and negative stiffness based on their geometric nonlinearity in elastic deformation. Traditionally, loading capacity and stiffness of this kind of structure tend to be relatively low, a drawback that can potentially be overcome by making section bistable beams varying along its length. However, there currently lacks a systematic evaluation on influences of the sectional alignment on its mechanical performance. Based on the chained constrained beam model, a simplified method for calculating the structure is derived in this paper. The method is validated by a series of tests. Using the method, a systematic parametric study is performed and optimization studies are conducted to establish the best achievable mechanical behavior of the bistable structure subjected to different design limitations. Influences of the stiffness of the lateral restraints on performance of the structure are also investigated. At last, a structure based on the bistable beams connected in parallel were designed using the proposed methodology and tested.