Analysis of sensitive wavelengths in railway vehicles with different inerter-based suspension systems

To enhance the dynamic performance and stability of high-speed railway vehicles, this study investigates the vibration attenuation mechanism of the transverse secondary inertial suspension System (TSISS). Based on vehicle–track coupled dynamics, models were established for a conventional suspension (Condition S1: parallel spring–damper) and four TSISS configurations (Condition S2: parallel inerter–spring–damper); an inerter in series with a damper, parallel to the air spring (Condition S3); an inerter in series with a spring, parallel to the air spring–damper (Condition S4); and a parallel spring–damper unit in series with an inerter, all parallel to the air spring (Condition S5). The analysis focuses on the response distribution of sensitive wavelengths under track irregularity excitations and their impact on ride comfort. Results indicate distinct frequency domain characteristics: Conditions S2 and S4 show sensitivity to short wavelengths (peaking around 20 m), improving ride quality indices by 11 % and 8 % over S1, respectively. Conversely, Conditions S3 and S5 target the longwave range, yielding improvements of 14 % and 28 %. Validated by coherence function analysis, Condition S5 significantly suppresses longwave irregularities (40–150 m), with a response peak near 105 m. Notably, with inertance set between 500 and 1000 kg, Condition S5 achieves a ride quality index of approximately 2.75 and substantially reduces lateral acceleration, demonstrating superior ride comfort.