Gradient and anisotropic design have proved to be two effective approaches for customizing lightweight porous parts in recent years due to their outstanding performances comparing to the uniform porous ones, such as high specific strength, specific surface areas and high energy and shock absorption capacities, . However, it is still challenging to integrate both gradient and anisotropy into a same porous part, while making it profile adaptable simultaneously. In this paper, a novel gradient anisotropic design method of Voronoi porous structures for parts customization is proposed driven by the stress field of a part in a specific application scenario. Firstly, the stress field is decomposed into a stress scalar field and a stress direction field. The former is mapped into the Voronoi site distribution by a weighted random sampling algorithm that globally controls the gradient of the mechanical properties, while the latter is applied to adjust the shapes and orientations of the Voronoi cells for tailoring the anisotropy locally. Then, a lightweight gradient anisotropic Voronoi porous (GAVP) part is customized based on a Voronoi cell growth strategy with preferred directions, making the porous part highly profile adaptable. Finally, the influences of the design parameters on the mechanical properties of the GAVP parts are analyzed in detail, and the proposed design method is further validated experimentally and numerically. The results show that the integration of gradient and anisotropy significantly enhances the mechanical properties of a GAVP part compared to the corresponding gradient porous or anisotropic porous ones, because our GAVP structure modeling method realize a more optimal allocation of material locally, which makes the stress distribution much more even.

中文翻译：

---

Voronoi 多孔结构的梯度各向异性设计


近年来，梯度设计和各向异性设计已被证明是定制轻质多孔零件的两种有效方法，因为它们与均匀多孔零件相比具有优异的性能，例如高比强度、比表面积以及高能量和减震能力。然而，将梯度和各向异性集成到同一个多孔部件中，同时使其轮廓具有适应性仍然具有挑战性。本文提出了一种由特定应用场景中零件的应力场驱动的用于零件定制的新型 Voronoi 多孔结构梯度各向异性设计方法。首先，将应力场分解为应力标量场和应力方向场。前者通过加权随机采样算法映射到 Voronoi 位点分布，全局控制机械性能的梯度，而后者用于调整 Voronoi 单元的形状和方向，以局部调整各向异性。然后，基于具有优选方向的 Voronoi 细胞生长策略定制轻质梯度各向异性 Voronoi 多孔 (GAVP) 零件，使多孔零件具有高度轮廓适应性。最后，详细分析了设计参数对GAVP零件力学性能的影响，并进一步通过实验和数值验证了所提出的设计方法。结果表明，与相应的梯度多孔或各向异性多孔零件相比，梯度和各向异性的集成显着提高了 GAVP 零件的机械性能，因为我们的 GAVP 结构建模方法实现了材料局部更优化的分配，从而使得应力分布更加均匀。