Investigation of mechanical behavior of nano clay doped laminated composite sheets

In this study, the mechanical behavior of nanoclay reinforced laminated composite sheets were investigated experimentally. In the study, woven fabric glass fiber reinforced epoxy composite sheets were used. The sheets were produced by the hand laying method by adding nanoclay depending on the epoxy weight. The study was carried out without additives, on boards obtained with nanoclay additives at 0.5%, 1%, and 1.5% by weight. Samples were obtained from the obtained plates following ASTM standards. These samples were then subjected to tensile test, compression test, shear test, and hardness test to determine the mechanical properties. In addition, Dynamic Mechanical Analysis (DMA) analyses, Differential Scanning Calorimetry (DSC), and Thermogravimetric Analysis (TGA) analyzes were also performed to evaluate the thermomechanical properties of composite samples. These properties were compared for all the samples (pure and with nanoclay) and the results are evaluated. At the same time, the SEM images of the samples were taken and the distribution of nanoclay was observed. The effect of nanoclay on the fracture types of the samples was also investigated. In the experimental study, obtained from nanoclay added samples; It was determined that the modulus of elasticity, shear modulus, tensile strength, shear strength, Poisson's ratio, and hardness values were higher than the values obtained from the samples without nanoclay. The effect of nanoclay on tensile strength increased by 26.97%, 31.06% and 21.73%, respectively, compared to the 0.5%, 1%, and 1.5% additive ratios of the undoped samples. The highest value in compressive strength values was obtained from the samples containing 1 wt% nanoclay. With the DSC analysis, it was determined that the tg temperatures increased as the nanoclay ratio increased compared to the tg temperature of the undoped sample. In the TGA analysis, at constant temperature values (300-490°C), the highest mass loss rate was obtained from the samples with a nanoclay ratio of 1.5% by weight. It was observed that the storage modulus decreased with the increase in temperature in all samples. In addition, as the nanoclay ratio increased, it was determined that there was a separation between the layers in the samples. Maximum results were obtained from the sample with 1.5% nanoclay in the loss module and from the sample with 0.5% nanoclay in the storage module. In addition, as the nanoclay ratio increased, it was determined that there was separation between the layers in the samples.