A multiscale modeling framework that integrates nanoscale-informed constitutive models is employed to predict the interlaminar and intralaminar enhancement in composite laminates with radially-grown carbon nanotube (CNT) architecture. The nanoscale-informed constitutive models are implemented using the high-fidelity generalized method of cells (HFGMC) technique accounting for the material constituents and imperfect interfaces at the microscale. The micromechanical model is then coupled with the finite element model of a composite laminate specimen at the macroscale. The developed computational modeling framework is exercised to predict the initiation and steady-state toughness of mode I fracture composite samples. The results obtained from the simulations are correlated to the available experimental data collected from the literature. Conclusions are presented comparing the model response of traditional fiber reinforced polymer (FRP) composite laminates and composites with radially-grown CNT architecture.