Abstract: In order to achieve the accurate prediction of composites' elastic constants, a numerical simulation method based on fiber-random-distribution micromechanical model is studied in this paper. Firstly, a modified random disturbing method is used to achieve the characterization of fibers' random distribution of the composite material, and the representative volume element (RVE) model with random fibers for the composite material is established in the finite element software. By applying periodic boundary conditions and using volume homogenization method, the prediction of elastic constants is achieved for two typical composite materials. The prediction results are compared with the prediction results of the traditional quadrilateral regular distribution model and the experimental data in literature. It shows that the fiber-random-distribution micromechanical model can achieve the prediction of composites' elastic constants with good accuracy. Besides, the numerical simulation results also show that the fibers' random distribution has less influence on the dispersion degree of composites' macroscopic elastic constants.

Key words: random disturbing, composites, RVE model, elastic constants, dispersion degree