Hybrid 3D-textile reinforced composites with tailored property profiles for crash and impact applications

Novel 3D-textile reinforced composites with a stretched fibre arrangement have very good specific mechanical properties and outstanding energy absorption capabilities. With respect to the specific technical requirements, 3D-textile preforms can be adjusted with regard to stiffness, strength and crash-worthiness by the intelligent combination of different fibre materials in the textile preform. Thus, hybrid 3D-textile preforms with tailored property profiles are excellent candidates for the use in impact and crash components of innovative lightweight structures for the aircraft and vehicle industry as well as for mechanical engineering applications. This article focuses on the investigation of the strain rate dependent material properties and failure behaviour of composites with hybrid multi-layered flat bed weft knitted fibre reinforcements consisting of different fibre combinations such as glass–glass, glass–aramid and glass–polyethylene. For this purpose, extensive impact tests and highly dynamic tension tests have been performed, which have been accompanied by ultrasonic investigations and microscopic analyses for the identification of failure modes and measures of damage.