Abstract For negative Poisson's ratio (NPR) cellular structures, most previous research focus on the design of unit cells, and then repeat the unit cell to construct uniform cellular structures. However, there is a disadvantage that these structures do not have much design freedom to achieve high-level functions, such as performing a desired deformation. As a solution, an evolutionary design method is proposed to develop nonuniform cellular structures. To conduct this method, the design domain is divided into finite unit cells with tunable Poisson's ratio (PR). With a given objective deformation, the value of each unit cell's PR is optimized using evolutionary algorithm (EA). In order to reduce the computational cost of the algorithm, discrete cosine transform (DCT) is applied to encode the structure for evolving. Considering the geometrical complexity of the optimized nonuniform cellular structures, additive manufacturing (AM) is chosen to build them physically. Both two-dimensional (2D) and three-dimensional (3D) design cases were developed and analyzed to validate the proposed method. The computational and experimental results showed good conformation with each other. Most importantly, this novel design method brings huge potential to NPR cellular structures with high-level functions and much wider applications.

中文翻译：

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具有优化泊松比分布的非均匀蜂窝结构的进化设计

摘要 对于负泊松比（NPR）细胞结构，以往的研究大多集中在单元格的设计上，然后重复单元格以构建均匀的单元格结构。然而，这些结构的缺点是没有太多的设计自由来实现高级功能，例如执行所需的变形。作为解决方案，提出了一种进化设计方法来开发不均匀的细胞结构。为了实施这种方法，设计域被划分为具有可调泊松比 (PR) 的有限单位单元。对于给定的客观变形，使用进化算法 (EA) 优化每个晶胞的 PR 值。为了降低算法的计算成本，应用离散余弦变换（DCT）对结构进行编码以进行进化。考虑到优化的非均匀蜂窝结构的几何复杂性，选择增材制造 (AM) 来物理构建它们。开发并分析了二维 (2D) 和三维 (3D) 设计案例，以验证所提出的方法。计算和实验结果显示出良好的构象。最重要的是，这种新颖的设计方法为具有高级功能和更广泛应用的 NPR 细胞结构带来了巨大的潜力。