Initial Damage‐Accountable Finite Element Modeling Approach for <scp>CFRP</scp> /Aluminum Riveted Joints

ABSTRACT Mechanical joints play a critical role in improving structural strength of composite structures. However, the complex nature of composite joints presents significant challenges. The manufacturing‐induced damage significantly affects their structural performance and is often neglected in structural simulations. This study proposes a refined finite element framework that explicitly considers initial damage for CFRP/Al riveted joints that explicitly account for drilling and riveting‐induced damage. Specifically, CFRP individual plies were discretized using solid elements and interlaminar interfaces were represented by cohesive elements, with contact interactions explicitly defined. Progressive damage was governed by the 3D‐Hashin and Johnson‐Cook criteria for the laminate and rivet, respectively. Drilling damage was represented as a ring‐shaped damage zone surrounding the hole, with interfacial stiffness degraded within the damaged region, thereby simulating delamination. Drilling delamination is characterized using an energy‐based equivalent damage diameter, while riveting‐induced stress, plastic deformation, and damage states are consistently transferred into subsequent tensile analysis through a predefined field and restart strategy. Quasi‐static tensile experiments, combined with X‐ray microscopy and 3D‐DIC measurements, demonstrate strong agreement between simulations and experiments in terms of load‐bearing capacity and failure modes. The results confirm that integrating manufacturing‐induced damage significantly enhances simulation prediction reliability and provides a unified process‐to‐structure modeling strategy with improved engineering applicability.