Numerical analysis of elastic–plastic properties of polymer composite reinforced by wavy and random CNTs

A geometric generation algorithm is proposed to produce the 3D finite element model to analyze the polymeric composite with randomly dispersed and wavy CNTs, typical in CNT/polymer composite. Considering the model randomness, the statistical criterion has been employed to determine the sample capacity, and then the critical size of FE models has been determined based on the degree of departure from isotropy and the statistical inhomogeneity. Moreover, a comparison is conducted among five types of FE models when CNT distribution is completely random; the differences are not evident among their predictions. However, when predicting the micro-field distribution inside materials, the beam models present a huge difference to the solid models. Furthermore, we explore the effect of the CNT length, orientation and waviness on the elastic–plastic properties of composite by using the FE model describing CNTs as effective continuum solid fibers, and then compare the FE predictions with experimental data.