The effect of salty water aging on low velocity impact behaviors of bolted halloysite nanotube-epoxy/basalt fiber nanocomposites

In this thesis, production of basalt fiber reinforced epoxy matrix (epoxy/BF) composite and halloysite nanotube (HNT) addition basalt fiber reinforced epoxy matrix (HNT-epoxy/BF) nanocomposite material were performed by using both hand laying and vacuum infusion method. In addition, the most efficient ratio of HNT used in epoxy matrix was found to be 2 % by weight as a result of tensile test of epoxy nanocomposite specimens. According to ASTM standards, the appropriate bolt connection system of the materials was made. Bolted epoxy/BF composite and HNT-epoxy/BF nanocomposite materials were left to aging in salty water for 2, 4 and 6 months. After the aging, the tensile test was carried out to examine the behaviors of the specimens under load, to observe the types of damage occurring and to find their load bearing capacities and also compared with non-aged specimens. Moreover, the low velocity impact test at room temperature was performed to for two different zones on the bolted composites and nanocomposites. The tests were applied at the energy levels of 15 J, 20 J and 25 J and the results compared to each other. The effects of salty water were investigated after the tensile and impact tests of composite and nanocomposite materials. The damages on the surface and fracture areas of the specimens were examined with optical microscopy and SEM images. It is observed that by reinforcing the HNT into the epoxy polymer, the tensile strength, elastic modulus and toughness properties of the epoxy nanocomposite material were increased. This was continued with basalt fiber introduced to the HNT reinforced epoxy. The bolted HNT-epoxy/BF nanocomposite materials showed superior performance compared to epoxy/BF composite material after tensile and impact test. Furthermore, after ageing, HNT-epoxy/BF nanocomposite materials were affected from salty water relatively less than epoxy/BF composite materials. This situation was came into prominence the fact that HNT serves as a buffer against salty water. Lastly, the epoxy/BF composite specimens had more damage density under the same conditions, when the optical and SEM images were viewed.