Study on mechanical properties of honeycomb pentamode structures fabricated by laser additive manufacturing: Numerical simulation and experimental verification
Study on mechanical properties of honeycomb pentamode structures fabricated by laser additive manufacturing: Numerical simulation and experimental verification
复制标题
激光增材制造蜂窝五模结构力学性能研究：数值模拟与实验验证
DOI：
10.1016/j.compstruct.2019.111199
复制
发表时间：
2019-10-15
影响因子：
6.3
通讯作者：
Shi, Yusheng
中科院分区：
文献类型：
--
作者：
Zhang, Lei;Song, Bo;Shi, Yusheng
本文对五模材料的模拟流体结构设计、形态特征、有限元法预测的应力分布、力学性能和变形机理进行了系统的研究。我们提出了两步优化策略来合理设计PM结构，色散曲线证实了得到的结构参数。采用选择性激光熔化（SLM）法制备了Ti-6Al-4V粉末粉末粉末结构。此外，由于slm制造的PM结构与设计的PM结构存在较小的偏差，因此采用改进的有限元模型对其应力分布和力学性能进行了预测。准静态压缩试验发现，随着支板宽度的增大，PM结构的变形机制由塑性断裂转变为尺寸效应导致的脆性断裂，这表明当支板宽度较小时PM结构具有较好的屈曲弹性。塑性-脆性过渡的临界支撑宽度估计为0.12 mm。这项工作将为蜂窝五模超材料的结构设计和定制力学性能铺平道路。
In this work, the structural design of mimicking the fluids, the morphological characteristics, stress distributions predicted by finite element (FE) method, mechanical properties and deformation mechanisms of pentamode materials (PMs) were systematically investigated. We proposed a two-steps optimization strategy to rationally design PM structures and the dispersion curves confirmed the obtained structural parameters. The designed PM structures made of Ti-6Al-4V powder were fabricated by selective laser melting (SLM). Besides, due to the slight deviations between the SLM-built PM structures and the designed ones, a modified FE model was used to predict the stress distributions and mechanical properties. Furthermore, from quasi-static compression tests, we find that as the strut widths increase, the deformation mechanism of PM structures transfers from plastic to brittle fracture resulting from the size effect, which indicates that PM structures would have a good elastic nature of buckling when the width of struts is small. The critical width of struts of plastic-to-brittle transition was estimated as 0.12 mm. This work would pave the way to structural design and customized mechanical properties of honeycomb pentamode metamaterials.