Multi-scale Modeling and Damage Analysis of Carbon Nanotube-Carbon Fiber-Reinforced Polymeric Composites

In the present study, the initiation and propagation of the damage in open-hole nano-composite laminates reinforced with carbon nanotube (CNT) and carbon fiber (CF) have been investigated using a multi-scale method. The fiber and matrix failure initiation is determined using Hashin-type 3D criteria, and the subsequent propagation is modeled using material-degradation law based on two methods. The computational models for the progressive damage modeling are implemented in the finite element (FE) code ABAQUS using user-defined field variable subroutine USDFLD. In order to estimate three-component nano-composite properties, first, the mechanical properties of CNT-reinforced polymeric nano-composite at a weight fraction of 0.5, 1, and 2% have been calculated using Molecular Dynamics (MD) method. Afterward, the CNT-reinforced polymeric nano-composite as an equivalent resin has been combined to a 45% volume fraction of CF, and the mechanical properties of the micro-scale three-component polymeric nano-composite have been calculated by applying periodic boundary conditions to the FE method. The required strength properties have also been calculated analytically using micromechanical equations. Subsequently, the damage and failure in nano-composite laminates containing a central hole subjected to uniaxial tension are simulated and analyzed. The results show the significant effect of CNT in increasing strength, improving the mechanical properties, and increasing damage resistance in three-component nano-composites. Numerical results also show that the damage model can accurately predict the behavior of progressive damage qualitatively and quantitatively.