• A novel co-simulation (CS) approach coupling CFD and MBD is proposed to capture fluid-structure interactions in high-speed trains, overcoming limitations of offline simulation (OS) that neglects vehicle motion effects on airflow.
• The CS method is validated against field test data, demonstrating its accuracy and reliability for analyzing aerodynamic and dynamic responses in complex scenarios such as tunnel exit under crosswind.
• Compared to OS, CS reveals significantly severer transient wheel-rail impacts and larger differences in aerodynamic moments (up to 29.6 kN·m in yawing), highlighting the importance of considering coupled effects for safety assessment.
• The CS approach offers superior computational efficiency and stability, making it a practical tool for studying high-speed train performance under extreme wind conditions and aiding in the design of safer railway operations.