Nanoreinforced polymer composites: 3D FEM modeling with effective interface concept

A computational study of the effect of structures of nanocomposites on their elastic properties is presented. The special program code for the automatic generation of 3D multiparticle unit cells with/without overlapping, effective interface layers around particles is developed for nanocomposite modeling. The generalized effective interface model, with two layers of different stiffnesses and the option of overlapping layers is developed here. The effects of the effective interface properties, particle sizes, particle shapes (spherical, cylindrical, ellipsoidal and disc-shaped) and volume fraction of nanoreinforcement on the mechanical properties of nanocomposites are studied in numerical experiments. The higher degree of particle clustering leads to lower Young’s modules of the nanocomposites. The shape of nanoparticles has a strong effect on the elastic properties of the nanocomposites. The most effective reinforcement is cylindrical one, followed by ellipsoids, discs, and last, spheres. Ideally random oriented and correlated microstructures lead to the same average Young moduli, yet, the standard deviation of Young modulus for correlated microstructure is nearly 4 times of that for fully random orientation case.