Understanding meso interfacial structures between z-pins and laminates in z-pinned laminates

• Published in: Composites communications 2022-11, Vol.35, p.101313, Article 101313
• Main Authors: Wang, Xiaoxu, Chen, Wen, Tang, Youhong
• Format: Article
• Language: English
• Subjects: Interface; Laminates; Meso structure; Z-pins
• ISSN: 2452-2139; 2452-2139
• DOI: 10.1016/j.coco.2022.101313

Z-pin pull-out tests from the laminates were conducted to explain the components of the meso interface structure of z-pin/laminate and the debonding position. Three types of z-pins with different molding qualities were investigated. The results revealed that the z-pin/laminate interface was composed of two meso interface components connected in series, including the interface between the outer layer resin of z-pin and the resin of laminate (Interface Ⅰ) and the interface between z-pin's own fiber and its own matrix resin (Interface Ⅱ). Debonding would occur at the weaker one. The z-pin with the best molding quality possessed the highest interfacial bond shear stress, τd, and the debonding mainly occurred at Interface Ⅰ. Regarding the z-pin with the worst molding quality, its τd was the lower one and the debonding primarily occurred at Interface Ⅱ. While this kind of z-pin exhibited the higher resistance at the final frictional pull-out stage. [Display omitted] •A new concept of meso interface structure between composite z-pin and laminate was proposed for the first time.•The interface of z-pin/laminate contains two meso interfaces, i. e., the interface between outer layer resin of z-pin and the resin of laminate (Interface Ⅰ), and the interface between z-pin's own fiber and its own matrix resin (Interface Ⅱ).•The z-pin with better molding quality possessed higher interfacial shear strength and lower maximum friction, and the debonding occurred at Interface Ⅰ. Regarding the z-pin with worse molding quality, the debonding occurred at Interface Ⅱ.