Abstract: To enhance the design freedom of the porous parts and elevate the matching rate between their interior mechanical property gradient and stress distribution,a stress driven 2.5D graded anisotropic Voronoi porous part design method was proposed.The Finite Element Analysis (FEA) result of the part was divided into a stress scalar field and a stress direction field.The stress scalar field was mapped into the distribution of the Voronoi sites in the part design domain through a proposed weighted random sampling method,making the materials and mechanical properties graded inside the part.After the stress direction field was transformed to a 2D Riemannian manifold,an anisotropic Voronoi diagram was established whose Voronoi cells were distributed along the Riemannian manifold through a proposed anisotropic Voronoi diagram modeling method with a preferred growth direction strategy.Based on the Voronoi diagram,the smooth graded anisotropic Voronoi porous part could be generated through offsetting,harmonic distance field and stretching algorithms in sequence.The mechanical properties of the Voronoi porous part was compared with two other types of porous parts through FEA method,three points bending tests and tensile tests,the results showed that the proposed method could enhance the matching rate between their interior mechanical property gradient and stress distribution,and reduce the material consumption of the part effectively.

Key words: lightweight design, porous structure, anisotropic, graded, Voronoi diagram

摘要： 为了提高多孔零件的设计自由度、内部力学性能梯度与实际应力分布的匹配度,提出一种应力驱动的2.5D梯度各向异性维诺多孔零件轻量化设计方法。将零件有限元分析结果分解为应力标量场和应力方向场,通过加权随机采样算法将应力标量场映射为零件设计域内的维诺站点分布,实现零件内部力学性能的梯度分布;将应力方向场映射为二维黎曼流形,提出一种基于胞元择优方向生长策略的各向异性维诺图生成算法,生成胞元沿黎曼流形分布的各向异性维诺图。在此基础上,通过偏置算法、调和距离场和拉伸算法生成光滑的梯度各向异性维诺多孔零件。最后,采用有限元分析、三点弯曲实验等方法将所设计的多孔零件和其他多孔零件进行比较分析。实验结果表明,所提出的梯度各向异性维诺多孔零件建模方法能有效提升零件内部力学性能梯度与实际应力分布的匹配度,降低材料消耗,实现轻量化设计。

关键词: 轻量化设计, 多孔结构, 各向异性, 梯度, 维诺图