Mechanical anisotropy of aligned fiber reinforced composite for extrusion-based 3D printing
Mechanical anisotropy of aligned fiber reinforced composite for extrusion-based 3D printing
复制标题
用于基于挤出的 3D 打印的定向纤维增强复合材料的机械各向异性
DOI：
10.1016/j.conbuildmat.2019.01.008
复制
发表时间：
2019-03-30
影响因子：
7.4
通讯作者：
Sanjayan, Jay
中科院分区：
文献类型：
--
作者：
Ma, Guowei;Li, Zhijian;Sanjayan, Jay
3D打印技术在建筑领域得到了广泛的研究。然而，关键问题在于开发具有良好的印刷性和足够的机械性能的胶凝材料，通过高强度和高延展性。在本研究中，首先根据合适的印刷适性，然后根据机械性能确定最佳玄武岩纤维含量。自行开发的3D打印机用于水泥材料的挤出，并且还用于通过保持喷嘴直径小于玄武岩纤维的长度来机械增强纤维沿打印方向的沿着排列。印刷过程沉积定向细丝，本质上导致层压结构和机械各向异性。印刷材料的各向异性性能进行了评估，基于方向的机械性能测试，并通过超声波脉冲速度测试确认。实验研究了3D打印样品在压缩、拉伸、弯曲和剪切载荷下的力学行为。通过先进的CT扫描技术检测打印样品的介观结构。提出了力学和声学指标来评价印刷材料的各向异性性能。特别是，力学各向异性性能和超声信号之间的经验关系建立。在微观结构水平上，通过扫描电子显微镜（SEM）成像，探讨了纤维排列、纤维拔出和纤维断裂的机械增强。(C)2019爱思唯尔有限公司版权所有。
3D printing techniques are being researched extensively in the construction sector. However, the key issue lies in the development of cementitious materials with both favorable printability and enough mechanical capability by means of high strength and ductility. In this study, an optimal basalt fiber content was determined basing firstly on suitable printability and then on mechanical performance. A self developed 3D printer was used for extrusion of the cementitious material and also for mechanical enhancement of fiber alignment along the print direction by keeping the nozzle diameter smaller than the length of the basalt fiber. The printing process deposits directional filaments, intrinsically resulting in laminated structures and mechanical anisotropy. Anisotropic performances of the printed material were evaluated by direction-based mechanical performance testing and confirmed by ultrasonic pulse velocity testing. The mechanical behaviors of 3D printed samples exposed to compressive, tensile, flexural and shearing loadings were experimentally investigated. The mesoscale structures of printed samples were detected through the advanced CT scanning technique. Both mechanical and acoustic indexes were proposed to evaluate the anisotropic properties of printed materials. In particular, empirical relationships between the mechanical anisotropic properties and ultrasonic signals were established. On the microstructural level, mechanical enhancement of fiber alignment, fiber pullout and fiber fracture were all probed through scanning electron microscope (SEM) imaging. (C) 2019 Elsevier Ltd. All rights reserved.