Effect of thermal bonding layers on interlaminar shear strength of laminated composites

Abstract

Abstract In this paper, the interlaminar shear strength (ILSS) of laminated composites with thermal bonding layers was measured by short beam shear (SBS) method to evaluate the effect of different contents of thermal bonding layers on the properties of laminated composites. It is characterized by using a certain interlacing law to lay the thermal bonding fibers into a regular mesh layer. By placing the thermal bonding layers between carbon fabrics, the two adjacent carbon fabrics can be bonded together by the thermal bonding layers through hot-press actions to help achieve overall integrity of preform with complex structure. This kind of special thermal bonding layers is prepared using thermoplastic nylon fiber (TPNF) with a low melting point. The thermal bonding layers were prepared with five different contents (2.08%, 4.17%, 6.25%, 8.33% and 10.42%) of TPNF. The resin transfer molding (RTM) process was used to prepare the laminated composites with thermal bonding layers. And the laminated composites without TPNF (0%) were also prepared as control group. Furthermore, the SBS test was conducted at room temperature. The experimental results show that the content of TPNF has a certain effect on the interlaminar properties of laminated composites, and 2.08% of TPNF increased the ILSS, indicating that proper addition of thermal bonding layer can not only help to achieve overall integrity of complex geometry shape preform, but also improve interlaminar properties of composites.