Damage model of carbon nanotubes debonding in nanocomposites

The progressive interfacial debonding between aligned carbon nanotubes and the hosting matrix of a nanocomposite in the direction normal to the CNTs axis is described by means of an equivalent constitutive model with evolutionary damage. The Eshelby-Mori-Tanaka theory is used to describe the macroscopic mechanical response of the nanocomposite for a given volume fraction of the different phases (i.e., perfectly bonded and fully debonded CNTs). The novelty of this work is the proposition of a new thermodynamically consistent phase flow law that describes the cumulative progression of debonding derived from the Weibull statistics. Monotonic and cyclic uniform strain histories are considered to investigate the nanocomposite response features such as the stress-strain softening hysteretic cycles, the progressive degradation of the elastic moduli, and the dissipated energy.