Effective Suppression of Friction-Induced Stick-Slip Vibration at Brake Interfaces of High-Speed Trains via Rational Selection of Disc Spring Materials

The friction-induced stick-slip vibration (FISSV) generated by intense friction between the brake disc and brake pads of high-speed trains is a critical issue affecting braking stability, the service life of foundational braking components, and ride comfort. The floating friction block structure, which effectively regulates interfacial contact characteristics through the elastic deformation of disc springs, thereby improving tribological behavior, represents an effective approach for mitigating FISSV. However, the topic of how to design the floating structure of the friction block to produce the best suppression impact on FISSV emerges, using the choice of disc spring material as an example. Thus, the purpose of this study is to look at how disc spring material affects stick-slip vibration (SSV) at the high-speed train floating brake interface. Four typical disc spring materials—304 stainless steel, Mubea-specific spring steel, 50CrVA high-alloy spring steel, and 60Si2MnA silicon-manganese spring steel—were selected. Through braking tribological tests and explicit dynamics-wear coupling simulations, the effects of material differences on interfacial friction-wear characteristics and SSV behavior were systematically studied. The findings show that the stiffness of the disc spring material greatly influences the dynamic responsiveness of the system and the contact pressure distribution at the braking interface, elasticity, and damping characteristics. 60Si2MnA spring steel, owing to its excellent elastic recovery and load equalization capability, promoted the formation of uniformly dispersed medium-to-small contact platforms on the interface, resulting in the mildest wear. Concurrently, its system vibration energy exhibited a more dispersed distribution in the frequency domain, with low SSV intensity and weak nonlinear behavior, demonstrating the best comprehensive performance. Materials with poorer compatibility, such as 304 stainless steel, tended to cause localized stress concentration, exacerbating wear and intensifying severe high-frequency SSV. The influence mechanism of disc spring material at the interface is shown by this work, providing an important basis for material optimization and vibration suppression design in floating brake pad structures.