Objective Vibration and noise generated by high-speed train body profiles significantly impact passenger comfort and surrounding environmental noise level. Due to the limited vibration reduction performance of traditional uniform beam structures, it is necessary to develop a new-type wedge-shaped acoustic damping structure, and establish a theoretical analysis model for studying its vibration reduction performance on train body profiles, aiming to optimize the structural parameters and enhance the damping efficiency.

Method First, based on the semi-analytical method using Gaussian function as the basis function, a theoretical analysis model for the wedge-shaped acoustic damping structure is established to calculate its modal shapes and vibration responses, and the accuracy of this model is verified via FEM (finite element method). On this basis, the effects of truncation thickness and power exponent on damping performance are investigated. Subsequently, an add-on acoustic damping system tailored for high-speed train body profiles is designed, and a complete coupled model of the train profile and damping system is established using FEM. Finally, by comparison with the conventional uniform beam damping system, reliability of the designed system is evaluated, and the influence of different parameters on the damping effect is analyzed.

Result & Conclusion  Because the truncation thickness and power exponent of the wedge-shaped damping structure significantly influence the vibration response, effective improvement of the damping performance can be achieved by reasonably optimizing these parameters. Compared to traditional uniform beam structures, the add-on acoustic damping system exhibits a superior damping effect with particularly prominent performance in specific frequency bands. Since the installation position of the damping system significantly impacts its performance, damping efficiency can be greatly improved by reasonable arrangement, while simply increasing the number of installations has very limited effect on enhancing the overall vibration reduction effect.