Topological and morphological design of additively-manufacturable spatially-varying periodic cellular solids
Topological and morphological design of additively-manufacturable spatially-varying periodic cellular solids
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DOI：
10.1016/j.matdes.2020.109155
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发表时间：
2020-11
影响因子：
8.4
通讯作者：
A. Tamijani;Shajayra Patricia Velasco;Lee Alacoque
中科院分区：
文献类型：
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作者：
A. Tamijani;Shajayra Patricia Velasco;Lee Alacoque
本研究的重点是创建一种方法来系统地生成空间变化的，周期性的，蜂窝状的微结构，这些微结构是量身定制的，以实现宏观结构的优化性能。用傅里叶级数展开表示单胞点阵，得到了相应的振幅谱和相位谱。然后，针对多个载荷情况优化每个单元的材料分布（拓扑）和方向（形态）。基于优化的取向更新空间谐波的相位，并且用优化的材料分布对模拟响应进行阈值化以找到二元晶格。该框架进行了测试，为三种类型的晶格具有不同的周期性。带矩形孔的正方形单元显示了单元正交各向异性特性在单一荷载工况下的应用;带三角形网格的三角形单元显示了其他类型单元和网格在多荷载工况下传递剪力的适用性;带五边形网格的正方形单元显示了框架的多功能性。通过增材制造优化后的三角形胞状实体，实验验证了与传统拓扑优化设计相比，优化后的三角形胞状实体刚度提高了12%，强度提高了57%。
The focus of this research is to create a methodology to systematically generate spatially-varying, periodic, cellular microstructures that are tailored to attain optimized performance of the macrostructure. The unit cell lattice is represented by Fourier series expansions, and the corresponding amplitudes and phase spectrum are obtained. Then, the material distribution (topology) and orientation of each cell (morphology) are optimized for multiple load cases. The phase of the spatial harmonics is updated based on the optimized orientation, and the analog response is thresholded with the optimized material distribution to find the binary lattices. The framework is tested for three types of lattices with various periodicities. The square cell with a rectangular hole shows the exploitation of the cell's orthotropic properties for structures subjected to a single load case; the triangular cell with the triangular lattice depicts the applicability of other types of cells and lattices to transfer shear for the structures subjected to multiple load cases; and the square cell with pentagonal lattices shows the versatility of the framework. An optimized triangular cellular solid is additively manufactured, and it is validated experimentally that 12% higher stiffness and 57% higher strength can be achieved compared to the conventional topology optimization design.