基于应变能动态聚类的梯度点阵结构优化设计

Optimization Design of Graded Lattice Structures Based on Dynamic Strain Energy Clustering

为了优化具有空间渐变几何特点的梯度点阵结构,促使有限材料在宏观结构中实现合理分布,提出结合动态聚类的两尺度并发拓扑优化方法。在整个优化过程中,微结构分区方式可以通过K-means聚类方法基于当前的宏观单元应变能进行聚类更新,获得比静态分区更为合理的微结构分布方式;并引入微结构转角变量,根据结构主应力方向来布置微结构转角,获得更为合理的宏观结构传力路径。数值算例表明,相较于传统指定材料区域的静态分区方法,该方法可以更为有效地进行材料分布,充分利用材料的各向异性,提升结构性能。

To optimize graded lattice structures with spatially graded geometrical characteristics and promote the rational distribution of finite materials in macrostructure,a two-scale concurrent topology optimization method combining dynamic clustering is proposed.Dynamic clustering strategy is developed to group microstructures,which means that the clustering pattern will be updated according to the current strain energy during the whole iterations and obtains a more reasonable microstructures’distribution than the static partition.Further,rotational degree of freedom is introduced to make sure that the microstructures are oriented along principal stress directions,so as to obtain a more reasonable load transfer path.Numerical examples show that,compared with the traditional static partition method,this method can more effectively distribute materials,make full use of the anisotropic of lattice structures,and improve structural performance.