Mechanical Properties of Nanocomposite based on Epoxy using Three Point Bending Test

The purpose of this paper is to investigate mechanical properties of Nanocomposite materials reinforced with carbon nano tubes (CNTs). This study considers the mechanical properties by three point bending test. The technique which is used in this study is one of the methods to calculate fracture toughness value. The specimens with four different mass percentages of carbon nano tubes were made. The mass percentages are 0%,0.01%, 0.05%, 0.1%, 0.2% and 0.3%. An ultrasonic device was used to disperse the CNTs uniformly in the epoxy matrix. So, the agglomeration of the CNT particles decreased in the matrix. In order to investigate the fracture toughness, same size cracks were created in two different directions on the specimens including low CNTs content grade and high CNTs content grade. Three point bending test was repeated at least three times for each of specimens. For each crack, there are different values of the fracture toughness and the fracture forces. Furthermore, the fracture surfaces of samples were investigated using scanning electron microscopy (SEM). The results showed that the direction of the crack, CNTs content and dispersion of the carbon nano tubes are important parameters. Also, flexural elasticity modulus that is different from tensile elasticity modulus was considered in this research.