Determination of mechanical properties of nanocomposites reinforced with spherical silica nanoparticles using experiments, micromechanical model and finite elements method

Abstract

In this research, experimental, numerical, and micromechanical methods are used to determine the effects of silica nanoparticle content on the elastic modulus of polymer matrix nanocomposites in tension and compression. The direct mixing method was used to prepare experimental samples containing 0.1, 0.25, and 0.5 volume fractions of silica nanoparticles. The elastic modulus of the nanocomposites is evaluated by the Einstein, Guth, Mori-Tanaka, Halpin-Tsai, Kerner, and Ji et al. micromechanical models. In addition, the elastic modulus of the nanocomposites is evaluated using the RVE method in ABAQUS software. The effects of volume fraction and diameter of silica nanoparticles, thickness, and adhesion exponent of the interphase on the elastic modulus of polymeric nanocomposite are extensively examined. Stiffer elastic modulus behavior is found in the presence of interphase region. The results indicate that the elastic modulus of nanocomposites reinforced with spherical silica nanoparticles is improved with increasing nanoparticle volume fraction, decreasing the nanoparticle diameter, increasing the interphase thickness, and decreasing the interphase adhesion exponent. The validity of the results of numerical and micromechanical models has been checked with experimental results. It can be seen that the results obtained from the experiments with 1 hour of ultrasonic waves in the tensile samples with volume fractions of 0.1, 0.25, and 0.5, compared to the pure sample, have increased by 5.4, 10.3, and 9.7 percent, respectively. Similarly, for compression samples with the same volume fractions, the results have increased by 7, 13, and 11 percent, respectively.