## 6 Conclusions  
This study evaluates the effectiveness and limitations of the GRCFBS method, which integrates generalized receptance coupling with FBS approaches. By developing explicit rotational DoFs, this approach improves the prediction accuracy of dynamic systems that experience both translational and rotational motions. Building on [PERSON]'s foundational work, the proposed framework introduces a practical, generalized formulation that explicitly incorporates full translational and rotational dynamics at each substructure node. This explicit formulation accounts for both translational and rotational displacements, enhancing the model's capability to predict the dynamic behavior of coupled systems more efficiently. The refinement of the GRCFBS method, which integrates rotational DoFs into the system formulation, provides a more comprehensive approach to capturing the dynamics of flexible structures and their interactions under complex loading conditions. This study focuses on two case studies: a flexible beam-beam coupling and a flexible beam-rigid wheel coupling, validating the performance of the GRCFBS method in these configurations. The results demonstrate that the GRCFBS method, when employing the EBT, accurately predicts system vibrational characteristics, especially at a lower range of frequencies (up to 2000 Hz), where it shows strong alignment with FEA. Specifically, the relative error in predicting resonance frequencies at lower frequencies is found to be less than 5%, indicating a high degree of accuracy for these ranges. Both direct and cross-receptance components show good agreement in predicting natural frequencies and dynamic responses. In the case of the beam-beam coupling, the presence of four resonance peaks and the higher response magnitudes are attributed to the inclusion of both translational and rotational DoFs, providing more complex dynamic behavior. While the GRCFBS method demonstrates strong agreement with FEA for both resonance and anti-resonance frequencies below 2000 Hz (with errors typically below 5%), discrepancies become apparent at higher frequencies (above 2000 Hz), where the accuracy decreases, resulting in relative errors exceeding 10% for non-rotational receptances. These discrepancies highlight the need for refinement of the theory of node receptance description in GRCFBS and the use of more accurate beam elements in FEA. Such advancements could better capture higher-order dynamic behaviors and further enhance the predictive accuracy of the method in these frequency ranges. However, both the FEA and GRCFBS methods exhibit similar trends in resonance and anti-resonance peaks, with a noticeable frequency shift observed beyond 2000 Hz. As an interesting observation, the rotational receptance components (both direct and cross) maintain a good agreement beyond 2000 Hz, confirming that the GRCFBS method remains accurate in predicting the rotational response at higher frequencies despite the overall magnitude discrepancies. To improve accuracy at high frequencies, future work could incorporate more advanced theories such as the Timoshenko beam theory, which accounts for shear deformation and rotational inertia, along with the inclusion of material damping, which plays a critical role in high-frequency vibration attenuation. In conclusion, while the GRCFBS method remains a valuable tool for dynamic system analysis, particularly at lower frequencies, future research should focus on enhancing its accuracy at higher frequencies. This could involve the integration of Timoshenko beam theory and improved damping models, enabling the method to better capture high-frequency behavior and extend its applicability to a wider range of structural configurations. Additionally, incorporating data-driven methods, such as machine learning (ML), holds great potential for improving the predictive capabilities and computational efficiency of this methodology, particularly in complex and real-world applications.