Progressive design of gradually stiffer metamaterial using surrogate model

Gradually stiffer metamaterial has great value in many applications such as transportation, construction and aviation due to their adaptive characteristics under nonlinear varying loads. However, complex deformation mechanisms and high non-linearity between parameters and performance in designing the gradually stiffer metamaterial hinder its development. This study proposes an efficient progressive design framework for the optimization of gradually stiffer metamaterial, in which topology optimization, parametric optimization and experiment analysis are considered as three main parts. Compared with the traditional design methods, the progressive design can reduce the design complexity and improve the optimization efficiency. For designing 3D gradually stiffer metamaterial, an initial configuration is obtained by the topology optimization. Then, the parametric optimization by means of an efficient global optimization algorithm based on the kriging surrogate model is developed to enhance the gradually stiffer property of the 3D periodic structure constructed by the initial configuration. Finally, the additive manufacturing is implemented to obtain various test pieces with typical structural parameters among the optimization process. Their mechanical characteristics are analyzed by compression experiments. Comparative analyses on the experimental and simulation data of various 3D structures demonstrate the effectiveness of the progressive design based on surrogate model in devising metamaterials with specific performances.