Design and Vibration Reduction Performance of Chiral Metamaterial Vibration-Damping Structure for High-Speed Train Floors

To address the insufficient low-frequency vibration reduction capability of high-speed train floor structures, a chiral metamaterial structure was proposed and fabricated as a substitute for wooden supports. The structure consists of an aluminum chiral load-bearing frame and an array of steel–rubber composite resonators. By reconfiguring vibration transmission paths through chiral topology and regulating energy transfer via local resonance, the proposed design aims to improve the dynamic behavior of the supporting path. Finite element simulations and shaker-table tests were conducted to compare the vibration transmission characteristics of chiral and grid structures, with and without resonators, and the vibration reduction performance was evaluated using vibration level differences. In addition, impact hammer tests were performed to investigate the dynamic response of a local floor system after replacing the wooden supports. The results show that the chiral topology enhances vibration energy redistribution and local coupling within the structure, while the introduction of resonators further broadens and strengthens the vibration reduction effect. Compared with the conventional wooden-support scheme, the proposed chiral metamaterial structure reduced the overall vibration response of the local floor by an average of 2.61 dB, with a maximum reduction of 11.94 dB. The proposed structure shows potential for low-frequency and broadband vibration reduction in highspeed train floor applications.