Z-pin insertion process for through-thickness reinforced thermoplastic composites
Z-pin insertion process for through-thickness reinforced thermoplastic composites
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DOI：
10.1177/0021998318781233
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发表时间：
2018-06
影响因子：
2.9
通讯作者：
J. Hoffmann;Alexander Brast;G. Scharr
中科院分区：
文献类型：
--
作者：
J. Hoffmann;Alexander Brast;G. Scharr
本文提出了一种新的方法，超声辅助插入金属z销到热塑性复合材料。对玻璃纤维增强聚酰胺和聚丙烯试样进行了力学和微观结构研究。将钢销插入热塑性复合材料导致微观结构的变化，这与z-钉扎热固性纤维增强塑料的已知微观结构显著不同。光学显微镜检查显示，每个针周围没有明显的纤维波纹和富含树脂的区域。相反，纤维主要是通过针穿透过程中产生的高插入力在整个厚度方向上偏转。为了获得初步了解所得到的性能的z-销/热塑性界面，Z-销的热塑性复合材料的力学性能的模式I加载下进行了研究，使用拔出试验。作为参考，热固性碳纤维增强塑料试件，用钢钉增强的拔出行为进行了测定。由于粘结不良和缺乏摩擦之间的销和层压板，热塑性试样的确定的牵引载荷远低于典型值实现从销拔出热固性层压板。
This paper presents a novel method for the ultrasonically assisted insertion of metallic z-pins into thermoplastic composites. Mechanical and microstructural investigations were carried out on glass fiber-reinforced polyamide and polypropylene specimens. The insertion of steel pins into thermoplastic composites led to microstructural changes that differ significantly from the known microstructure of z-pinned thermoset fiber-reinforced plastics. Optical microscopy showed an absence of notable fiber waviness and resin-rich zones around each pin. Instead, the fibers were predominantly deflected in the through-thickness direction by the high insertion forces arising during pin penetration. To gain an initial insight on the resulting properties of the z-pin/thermoplastic interface, the mechanical properties of z-pinned thermoplastic composites under mode I loading were investigated using pullout tests. For reference, the pullout behavior of thermoset carbon fiber-reinforced plastic specimens, reinforced with steel pins was determined too. Due to the poor bonding and lack of friction between the pin and laminate, the determined traction loads of the thermoplastic specimens are well below typical values achieved from pin pullout in thermoset laminates.