Effect of Ø 0.11 mm Z-pinning on the properties of composite laminates via an ultrasound guided insertion process. (8th September 2021)

• Record Type: Journal Article
• Authors: Fei, Shaohua; Wang, Weiwei; Wang, Han; Yang, Di; Ding, Huiming; Wang, Haijin; Li, Jiangxiong; Ke, Yinglin
• Is Part Of: Composites science and technology. Volume 213(2021)
• Publication Date: 2021-09-08
• Subjects: Laminate -- Fracture toughness -- Mechanical properties -- Finite element analysis (FEA) -- Z-pin; Composite materials -- Periodicals; Composite materials; Fibrous composites; Periodicals; 620.118
• DOI: 10.1016/j.compscitech.2021.108906
• Languages: English
• ISSNs: 0266-3538

Abstract

Abstract: This paper develops an ultrasound guided Z-pinning process, which can insert finer Z-pins of Ø 0.11 mm (in comparison with traditional Ø 0.28 mm - 0.50 mm) with minimal in-plane damage and substantially improve the interlaminar performance of Z-pinned composite laminates. The experimental results show that for unidirectional fibre/epoxy laminates reinforced by 0.1 vol% of Ø 0.11 mm carbon Z-pins, the in-plane strength reduction is only 1.31% in tension and 3.46% in compression, respectively, while the Mode-I fracture toughness can be improved by 11 times in comparison with the unpinned specimens. The results can be attributed to the small damage to the microstructures of the pinned area, where long and narrow resin-rich zone with small in-plane fibre waviness and neglectable out of plane fibre crimp are represented. The interlaminar toughening mechanism of fine Z-pinned laminates is elucidated by the bridging law with the establishment the DCB testing model based on the traditional Z-pin reinforcement mechanism. Graphical abstract: Image 1 Highlights: An ultrasound guided Z-pin insertion process is developed to insert Ø 0.11 mm carbon Z-pins into composite laminates. The in-plane strength reduction of fine Z-pinned laminates is only 1.31% in tension, and 3.46% in compression. The Mode-I fracture toughness is improved by 11 times in comparison with the unpinned specimens.