Topology optimization of microlattice dome with enhanced stiffness and energy absorption for additive manufacturing
Topology optimization of microlattice dome with enhanced stiffness and energy absorption for additive manufacturing
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DOI：
10.1016/j.compstruct.2020.112889
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发表时间：
2021
影响因子：
6.3
通讯作者：
Jingwei Zhang;J. Yanagimoto
中科院分区：
文献类型：
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作者：
Jingwei Zhang;J. Yanagimoto
增材制造 (AM) 与拓扑优化的协同作用已成为开发具有高能量吸收能力的超轻、超刚性结构的有用方法。为了提高通常用作夹层板核心的传统圆顶的重量比刚度和能量吸收能力，提出了一种用拉伸主导的微晶格填充圆顶固体部分的新概念。将基于均质化的拓扑优化方法与晶格结构相结合，得到了微晶格的最优密度分布。优化后的变密度微晶格圆顶的压缩刚度和弯曲刚度比传统实心圆顶高41.8%和33.7%，而微晶格圆顶在压缩和三点弯曲过程中的能量吸收分别增加297.5%和85%。对单元尺寸对微晶格圆顶机械性能影响的研究表明，在给定的总体积分数约束下，较大的单元尺寸对特定重量的刚度和能量吸收能力的贡献更大。本文描述的拓扑优化和构造方法具有通用性，可用于进一步开发以微晶格为组成单元的任意宏观形状的超轻、超硬结构。
The synergy of additive manufacturing (AM) with topology optimization has become a useful method for developing ultralight, ultrastiff structures with high energy absorption capability. To improve the weight-specific stiffness and energy absorption capability of the conventional dome commonly used as the core of sandwich sheets, a new concept of filling the solid part of the dome with stretch-dominated microlattices is proposed. The optimal density distribution of microlattices is obtained by integrating the homogenization-based topology optimization method with the lattice structure. The compressive and bending stiffnesses of the optimized variable-density microlattice domes are demonstrated to be 41.8% and 33.7% higher than those of the conventional solid domes, while the energy absorption of the microlattice dome during compression and three-point bending is increased by 297.5% and 85%, respectively. Investigation of the cell size effect on the mechanical properties of the microlattice dome reveals that a larger cell size contributes more to the weight-specific stiffness and energy absorption capability at a given overall volume fraction constraint. The topology optimization and construction methods described in this paper are universal and can be used for the further development of ultralight, ultrastiff structures with arbitrary macro shapes with microlattices as constituent units.