This dissertation presents an advanced study on the use of constitutive polymer models within a multiscale framework, aimed at the virtual analysis of damage mechanisms in unidirectional composites. By applying finite element modeling (FEM) for multiscale analysis, the study seeks to gain an improved predictive understanding of failure behaviors in fiber-reinforced polymer (FRP) composites. Central to this approach is the integration of micromechanical models based on representative volume elements (RVEs) that include fibers, the polymer matrix, and fiber-matrix interfaces. This integration is crucial for correlating micro-level damage mechanisms with macroscopic damage observations, thereby improving the accuracy of predictions regarding material performance and delamination resistance. The research develops a comprehensive computational framework that simulates experimental setups at the coupon scale, using multiscale modeling techniques to provide a detailed expression of the mechanical response of FRP laminates. By incorporating a cohesive traction-separation interaction law to describe interfacial behavior, the dissertation enriches the understanding of fracture mechanics within the laminate, allowing for a detailed analysis of internal architecture and fracture behavior. Overall, this work makes a significant contribution to the field by enhancing the mechanical performance of FRP composites through advanced computational strategies, highlighting the importance of a multiscale approach in predicting and understanding the complex behaviors of composite materials.