Multi-level micromechanics-based homogenization for the prediction of damage behavior of multiscale fiber-reinforced composites

A multi-level micromechanics-based homogenization is proposed here to investigate the damage behavior of composites with multiscale fibers such as carbon nanotube (CNT) and carbon fiber. First, a molecular unit cell is constructed considering the interfacial characteristics between the CNT and a polymer matrix, after which molecular dynamics simulation and micromechanics are utilized to obtain the elastic properties of CNT-reinforced composites. A micromechanics-based progressive damage model is then adopted to predict the damage behavior of the CNT and carbon fiber-reinforced composites. Tensile tests are also conducted to investigate the stress-strain behaviors of the composites. To verify the applicability of the proposed model, the present predictions are compared with those obtained from the tensile test results. The proposed multi-level homogenization has shown to provide a close match to the experimental results. The proposed modeling scheme may facilitate a thorough investigation of the damage behavior of multiscale fiber-reinforced composites, proving the importance of each constituent at a different level.