Yan Leilei, Zhu Keyu, Zhang Yunwei, Zhang Chun, Zheng Xitao
School of Aeronautics, Northwestern Polytechnical University, Xi'an 710072, China.
Aeronautics Engineering College, Air Force Engineering University, Xi'an 710051, China.
Polymers (Basel). 2020 Sep 10;12(9):2059. doi: 10.3390/polym12092059.
Polylactic acid (PLA) hexagonal honeycomb structures were fabricated by using 3D-printing technology. By filling with absorbent polymethacrylimide (PMI) foam, a novel absorbent-foam-filled 3D-printed honeycomb was obtained. The in-plane (L- and W-direction) and out-of-plane (T-direction) compressive performances were studied experimentally and numerically. Due to absorbent PMI foam filling, the elastic modulus, compressive strength, energy absorption per unit volume, and energy absorption per unit mass of absorbent-foam-filled honeycomb under L-direction were increased by 296.34%, 168.75%, 505.57%, and 244.22%, respectively. Moreover, the elastic modulus, compressive strength, energy absorption per unit volume, and energy absorption per unit mass, under W-direction, also have increments of 211.65%, 179.85, 799.45%, and 413.02%, respectively. However, for out-of-plane compression, the compressive strength and energy absorption per unit volume were enhanced, but the density has also been increased; thus, it is not competitive in energy absorption per unit mass. Failure mechanism and dimension effects of absorbent-foam-filled honeycomb were also considered. The approach of absorbent foam filling made the 3D-printed honeycomb structure more competitive in electromagnetic wave stealth applications, while acting simultaneously as load-carrying structures.
采用3D打印技术制备了聚乳酸（PLA）六角形蜂窝结构。通过填充吸收性聚甲基丙烯酰亚胺（PMI）泡沫，得到了一种新型的填充吸收性泡沫的3D打印蜂窝。对其面内（L向和W向）和面外（T向）压缩性能进行了实验和数值研究。由于填充了吸收性PMI泡沫，填充吸收性泡沫的蜂窝在L向的弹性模量、抗压强度、单位体积能量吸收和单位质量能量吸收分别提高了296.34%、168.75%、505.57%和244.22%。此外，在W向，弹性模量、抗压强度、单位体积能量吸收和单位质量能量吸收也分别提高了211.65%、179.85、799.45%和413.02%。然而，对于面外压缩，抗压强度和单位体积能量吸收有所提高，但密度也增加了；因此，其单位质量能量吸收没有竞争力。还考虑了填充吸收性泡沫的蜂窝的失效机制和尺寸效应。吸收性泡沫填充的方法使3D打印蜂窝结构在电磁波隐身应用中更具竞争力，同时还能作为承载结构。
