Purpose <p>Structural Health Monitoring (SHM) plays a critical role in evaluating the integrity of structures under both static and dynamic conditions. In particular, the detection of damage in connections such as concrete–steel and steel–steel joints commonly implemented using bolts, screws, plugs, and nails is essential to ensure structural safety and avoid catastrophic failures. This study aims to improve the identification of localized damage in these types of joints by employing vibration-based and static load methods.</p> Methods <p>The proposed approach utilizes the Difference in Mode Shape Curvature (DMC) method, enhanced by a new stiffness matrix tailored for linear connectors. By treating the joint between the solid materials (concrete or steel) and linear connectors as rigid, rotational degrees of freedom (DOFs) in the connectors are eliminated and replaced with equivalent translational DOFs. This reformulation allows for more accurate modeling of real structural behavior. Additionally, three metaheuristic optimization techniques are applied to improve the accuracy of damage quantification and localization, with varying boundary conditions, population sizes, and iteration counts considered.</p> Results <p>The numerical and comparative studies reveal that the Dynamic Beetle Optimization (DBO) algorithm provides superior performance in terms of damage localization accuracy compared to the other two tested methods. The DMC indicator, when combined with the updated stiffness modeling and optimized search process, enhances the sensitivity and reliability of the damage detection procedure.</p> Conclusion <p>The integration of an improved stiffness model for linear connectors and the application of DBO optimization within the DMC framework presents a promising tool for detecting damage in critical structural joints. This methodology offers valuable insights for the development of more robust SHM systems for complex composite structures in engineering applications.</p>