Chen Wenjiong, Zheng Xiaonan, Liu Shutian
State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian 116024, China.
Materials (Basel). 2018 Oct 23;11(11):2073. doi: 10.3390/ma11112073.
A parameterization modeling method based on finite element mesh to create complex large-scale lattice structures for AM is presented, and a corresponding approach for size optimization of lattice structures is also developed. In the modeling method, meshing technique is employed to obtain the meshes and nodes of lattice structures for a given geometry. Then, a parametric description of lattice unit cells based on the element type, element nodes and their connecting relationships is developed. Once the unit cell design is selected, the initial lattice structure can be assembled by the unit cells in each finite element. Furthermore, modification of lattice structures can be operated by moving mesh nodes and changing cross-sectional areas of bars. The graded and non-uniform lattice structures can be constructed easily based on the proposed modeling method. Moreover, a size optimization algorithm based on moving iso-surface threshold (MIST) method is proposed to optimize lattice structures for enhancing the mechanical performance. To demonstrate the effectiveness of the proposed method, numerical examples and experimental testing are presented, and experimental testing shows 11% improved stiffness of the optimized non-uniform lattice structure than uniform one.
提出了一种基于有限元网格的参数化建模方法，用于为增材制造创建复杂的大规模晶格结构，并且还开发了一种相应的晶格结构尺寸优化方法。在该建模方法中，采用网格划分技术来获取给定几何形状的晶格结构的网格和节点。然后，基于单元类型、单元节点及其连接关系，对晶格单胞进行参数化描述。一旦选择了单胞设计，就可以通过每个有限元中的单胞来组装初始晶格结构。此外，可以通过移动网格节点和改变杆件的横截面积来对晶格结构进行修改。基于所提出的建模方法，可以轻松构建渐变和非均匀的晶格结构。此外，提出了一种基于移动等值面阈值（MIST）方法的尺寸优化算法，以优化晶格结构，提高其力学性能。为了证明所提方法的有效性，给出了数值算例和实验测试，实验测试表明，优化后的非均匀晶格结构的刚度比均匀晶格结构提高了11%。
