The effect of nanoparticles in single-lap composite joints studied by experimental and numerical analyses

This study aimed to investigate the effect of nanoparticles on the strength of single-lap nanocomposite joints. Three different types of specimens were studied, each of which contained 1 wt% of carbon nanotube in the adhesive. The adherends included three different percentages of nanoclays, namely 0, 5 and 7 wt%. The material used here was glass fibers/epoxy, with epoxy as the matrix. After fabrication of the laminates, they were stuck together by epoxy resin containing 1 wt% of carbon nanotube. Different tests were also conducted to analyze the specimens. These tests included X-ray diffraction (XRD), scanning electron microscope (SEM) and tensile test. In the XRD test, the presence of glass fiber, epoxy resin and nanoclays was verified and in the SEM test, the distribution of nanoclays into the laminates was investigated and finally the strength of the joints with different nanoparticles was examined by tensile test. In addition, a finite element (FE) analysis was also incorporated and the results of this method were verified by the experimental results. To perform the FE analysis, Young's modulus of the laminates and the adhesive were both required. Therefore, a tensile test was conducted to obtain the Young's modulus of the adherends and the elastic modulus of adhesive was obtained from the data existing in the literature. Finally, the results from FE analysis and the experimental tests were compared with each other and a good agreement was observed. It was finally concluded that the specimen comprised of 5 wt% nanoclays had the best performance among the three.