A study on the potential of NCF thermoplastic composites for use in aeronautic structural applications

Abstract

Abstract An investigation on the behavior of four new non-crimp fabric (NCF) composite materials developed by using the thermoplastic resin polyetheretherketone (PEEK) was performed with the aim to assess their potential for producing structural airframe parts of the required quality at reduced cost. In this framework, the mechanical behavior as well as the hot forming behavior of the materials developed was experimentally investigated. In addition, the draping behavior of the NCFs was experimentally evaluated to assess their suitability for being exploited in composite component manufacturing technologies involving direct lay-up processes. To better understand the behavior observed, both C-scan ultrasonic and optical microscopy analyses were performed. Furthermore, a complete series of tests was also carried out for the thermoplastic composite APC-2/AS4 to obtain a reference for comparison. The results of the test have shown that the mechanical properties of thermoplastic NCFs compare well with the respective properties of the reference material. Furthermore, the promising results of the hot forming tests support the expectation of using thermoplastic NCF composites in aircraft structural parts. Finally, the improved drapeability of the NCF material allows for a direct lay-up in a curved form tool. In conclusion, the developed thermoplastic NCF composites show a clear potential to compete with the established aeronautical prepreg material APC-2/AS4.