Damping properties of flax/carbon hybrid epoxy/fibre-reinforced composites for automotive semi-structural applications.

The ever-increasing demand for environmentally friendly biocomposites for use in various engineering applications requires a strong understanding of these materials properties, especially in automotive applications. This study focused on investigating how the stacking sequence and fibre orientation impacts the damping properties of hybrid flax/carbon fibre-reinforced composites. Different hybrid carbon fibre/flax fibre-reinforced composites using epoxy resin as the matrix were manufactured using vacuum-assisted resin infusion moulding technique. Each composite material was then tested for tensile properties using a universal testing machine, and the damping experiment was conducted using an impulse hammer and a Laser Doppler Vibrometer. The tensile study found out that adding a flax layer to the external layers of carbon fibre laminate reduced Young’s modulus by 28% for one layer and 45% for two layers. It was noted that when the fibre orientation of the internal layer of [C/F2/C]s was replaced with two ±45° layers, this had a very little effect on Young’s modulus but reduced the ultimate tensile strength by 61%. This experimental study also showed that the most important layer when it comes to damping properties is the external layers. By adding an external flax layer into an epoxy/carbon fibre-reinforced composite considerably enhanced its damping ratio by 53.6% and by adding two layers increased it by 94%. The results indicated a high potential for the automotive semi-structural applications to improve damping properties of the vehicle