Finite element modeling of fatigue properties of polymer nanocomposites

Abstract

This paper presents a 3-dimensional finite element modeling of fatigue properties of polymer nanocomposites with a Representative Volume Element (RVE) approach using ANSYS. Epoxy was used as a matrix, and alumina nanoparticles of spherical shape (diameter 33 nm) were used as reinforcement. Convergence analysis was conducted to select the proper size of RVE. A geometric model of a flat dog bone specimen was created to model the fatigue properties. MATLAB code was used to generate randomly distributed nanoparticles. The sample was loaded in uniaxial tension-tension fatigue loading with a stress ratio of 0.1. S-N data for epoxy and alumina were given as input to determine the fatigue life of polymer nanocomposites. The results obtained from modeling were compared with experimental data. The fatigue life was determined by taking the average life at five different locations in the gauge region for a sample. The average of five different samples was calculated for each wt.% (0.5, 1.0, and 1.5). Reinforcement of nanoparticles up to 1 wt.% caused an increment in the fatigue life of nanocomposites, and fatigue life decreased at 1.5 wt.% of nanoparticles. The finite element modeling was able to predict the trend of improvement provided by the alumina nanoparticles (similar to experimental data).