Abstract
Mechanical strength simulation techniques for nanocomposite resins have been developed. Coarse grained molecular dynamics are used to calculate the nanofiller distribution in resin and the stress-strain curve (S-S curve) of nanocomposite resin. A molecular orbital method based on density functional theory in which the electrical fields from a large region (μm-mm) of surrounding resin are taken into consideration to obtain the inter-molecular forces for molecular dynamics. In addition, present simulations were applied to silica/epoxy nanocomposite resins and the following results were obtained. (1) While hydrophilic silica is uniformly distributed, hydrophobic silica forms a network in epoxy. These results agree with an experimental observation using scanning electron microscope. (2) The maximum level of stress of the calculated S-S curves of resin with hydrophobic silica is greater than that with hydrophilic silica. This result qualitatively agrees with the fracture-toughness measured by using a three-point bending test.
