Micromechanical modeling of nanocomposites considering debonding and waviness of reinforcements

This paper deals with a constitutive model of carbon nanotube (CNT)-reinforced composites which describe the debonding damage and waviness effects of reinforcements on mechanical properties of nanocomposites simultaneously. It is observed that the lack of fiber waviness distribution and weak bonding assumption lead to inaccurate composite stiffness prediction. Based on the present model, analysis of stress–strain response for CNT/polymer composites under uniaxial tension is carried out. At constant strains while considering interfacial debonding of inclusions, CNT-reinforced composites with more curved CNTs have additional area under the curve and therefore accomplish higher toughness. In presence of poor bonding, CNT waviness can enhance the composite stiffness rather than reducing it. A quite different conclusion with respect to what can be obtained with the assumption of perfect bonding. Moreover, the waviness and interfacial debonding of inclusions have effect on Poisson’s ratio of CNT-reinforced nanocomposites. The Poisson’s ratio decreases first then it increases by increasing the waviness parameter.