Z-Pinned composites with combined delamination toughness and delamination Self-Repair properties
Z-Pinned composites with combined delamination toughness and delamination Self-Repair properties
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DOI：
10.1016/j.compositesa.2021.106566
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发表时间：
2021-08-03
影响因子：
8.7
通讯作者：
Mouritz, A. P.
中科院分区：
文献类型：
--
作者：
Loh, T. W.;Ladani, R. B.;Mouritz, A. P.
z 形钉扎层压板和其他类型的具有全厚度纤维增强的复合材料（例如 3D 编织纱线、缝线、簇绒）的损坏无法使用传统方法修复。为了克服这个问题，我们开发了一种新型的 z 钉扎复合材料，它独特地结合了薄的热塑性可修复长丝，在使用热激活后，可以修复分层损坏。我们使用 z 钉扎复合材料演示了这项技术，该复合材料含有碳纤维基层，其中含有低比例的由聚[乙烯-共-(甲基丙烯酸)] (EMAA) 组成的热塑性长丝。碳层中包含可修复的 EMAA 细丝，由于其钉扎、偏转和分支分层裂纹的能力，提高了 z 钉扎复合材料的 I 型层间断裂韧性。相对于对照样本，通过在 z 钉扎复合材料的碳纤维中包含 EMAA，裂纹萌生和裂纹扩展的 I 型层间韧性值大大增加（分别超过 230% 和 750%）。适度加热后，EMAA 激活了可修复的愈合过程，修复了分层损伤并部分恢复了 I 型韧性特性。这种新颖的修复工艺对于任何类型的含有全厚度增强材料的复合材料都有潜在的应用，包括 3D 编织、缝合、簇绒和 Z 形锚定材料。
Damage to z-pinned laminates and other types of composite materials with through-the-thickness fibre reinforcement (e.g. 3D woven yarns, stitches, tufts) cannot be repaired using conventional methods. To overcome this problem, we have developed a new type of z-pinned composite that uniquely incorporates thin thermoplastic mendable filaments which, upon activation using heat, can repair delamination damage. We demonstrate this technology using a z-pinned composite material containing carbon fibre based ply layers containing a low fraction of thermoplastic filaments composed of poly[ethylene-co-(methacrylic acid)] (EMAA). The inclusion of mendable EMAA filaments in the carbon plies increased the mode I interlaminar fracture toughness of the zpinned composite material due to their capacity to pin, deflect and branch delamination cracks. The mode I interlaminar toughness values for crack initiation and crack propagation were increased greatly (by over 230% and 750% respectively) by the inclusion of EMAA in the carbon fabric to the z-pinned composite relative to the control specimen. Upon moderate heating, the EMAA activated a mendable healing process that repaired the delamination damage and partially restored the mode I toughness properties. This novel repair process has potential application for any type of composite containing through-thickness reinforcement, including 3D woven, stitched, tufted and z-anchored materials.