The effect of micromechanics models on mechanical property predictions for short fiber composites

The Tandon-Weng (T-W), the Halpin-Tsai (H-T) micromechanical models and a novel numerical implementation of asymptotic homogenization method (NIAH) for determining the stiffness of unidirectional orientation short fiber composites are compared. Based on rigorous mathematical theory, NIAH can be easily implemented using commercial software as a black box as representative volume approaches. Representative volume element (RVE) models were generated using random sequential adsorption technique (RSA) based on the optimal Latin hypercube sampling method. For arbitrary fiber orientation, the NIAH approach was compared with orientation averaging with the T-W and the H-T micromechanical models. Agreement between the three approaches in predicting the effective properties of short fiber composites was found to be excellent. Finally, the results calculated with the three approaches were compared with experimental values. It is shown that the three approaches in this paper are in quite good agreement with measured values. However, for random oriented short fiber composites with fiber length and fiber diameter distribution, the NIAH method still can provide calculated results with sufficient prediction accuracy, and the other two methods are not any more effective.