Brake-interface tribology and stick–slip vibration in high-speed trains with triangular support design

• Triangular support structures were designed and experimentally investigated. • Dynamic wear analysis method was developed and validated for tribology–vibration analysis. • PTS structure was shown to suppress FISSV, and enhance tribological behavior and braking stability. • Brake pad performance can be enhanced through optimized triangular support design. High-speed train brake pads widely adopt triangular support (TS) structures to manage the severe thermal and mechanical loads during friction braking. However, under low-speed and high-friction conditions, friction-induced stick–slip vibration (FISSV) can arise, leading to instability, uneven wear, and noise, which severely affect driving safety and comfort. To reveal its tribological and dynamic mechanisms, this work comparatively investigates the positive triangular support (PTS) and inverted triangular support (ITS) arrangements through FISSV simulation experiments and multi-source dynamic wear simulations. Results show that the TS structure significantly affects interfacial wear morphology. The PTS arrangement produces shallow exfoliation pits (smaller than 50 μm), compact and continuous plateaus dominated by large areas (greater than 8000 px²), and a uniform stress field with maximum about 1.88 MPa. In contrast, the ITS arrangement leads to deeper pits (greater than 60 μm), discontinuous plateaus dominated by small areas (smaller than 500 px²), and severe stress concentration (greater than 3.08 MPa). These differences establish that PTS enhances plateau compaction and stiffness, while ITS accelerates surface fragmentation and wear. The TS structure also regulates friction-induced stick–slip vibration (FISSV). Under PTS, vibration intensities remain low (lower than 50 mm/s²) with dispersed frequency peaks at 40.2 Hz and 125.7 Hz, whereas ITS causes high vibration (greater than 100 mm/s²) with dense high-frequency components clustered around 142.8 Hz and 290.5 Hz. This indicates that PTS weakens resonance and stabilizes stick–slip transitions, while ITS amplifies oscillations and instability. Furthermore, a dynamic wear simulation method incorporating multiple friction sources is developed. By coupling ALE + Explicit algorithms, the method successfully reproduces the redistribution of stress and evolving wear states across multiple blocks, with results (wear depth <50 μm vs. >60 μm; stress 1.88 MPa vs. 3.08 MPa) consistent with experiments. This approach provides a robust tool for revealing FISSV mechanisms and offers engineering guidance for optimizing brake pad structures to enhance safety and comfort in high-speed trains. This study reveals the significant influence of different TS structure arrangements on FISSV and friction-wear characteristics, providing theoretical basis and engineering guidance for optimizing high-speed train brake pad design, suppressing vibration noise, and enhancing braking performance. In addition, the research method established in this work for investigating interfacial friction–wear behavior and FISSV under multi-source excitation can be further applied to brake system of high-speed trains.