Micromechanical elastoplastic analysis of randomly oriented nonstraight carbon nanotube-reinforced polymer nanocomposites

An elastoplastic constitutive model is proposed to evaluate the overall behavior of randomly oriented wavy carbon nanotube (CNT)-reinforced polymer nanocomposites under uniaxial and biaxial loadings. For an accurate prediction of the nanocomposite elastoplastic behavior, considering randomly oriented wavy CNTs into the matrix is essential. Effects of volume fraction, diameter, aggregation, and nonstraight state of the CNTs, thickness and adhesion exponent of the CNT/polymer interphase on the nanocomposite elastic-plastic stress-strain curves are investigated. The nanocomposite strengthening is improved with (1) increasing CNT volume fraction, (2) applying straight CNTs, (3) decreasing the CNT diameter, and (4) increasing the interphase thickness.