Ali Sercan KESTEN and Burak AYVA
Abstract – This study examines the effect of railpad stiffness on ground-borne vibration levels in railway systems under varying operational conditions. A theoretical modeling framework is developed to quantify how variations in railpad stiffness influence vibration transmission as a function of train speed and axle load, with the objective of informing railpad selection in railway design applications. The track–vehicle interaction is represented using a Euler–Bernoulli beam theory formulation for the rail, supported by discrete elastic components that simulate the railpad–support system. Train-induced excitation is modeled within a stochastic (random vibration) framework to capture the dynamic and irregular nature of loading. Ground-borne vibration responses are computed across a range of railpad stiffness values, operational speeds, and vehicle weights, enabling a systematic comparison of vibration behavior under realistic operating conditions. The results indicate that railpad stiffness is a key parameter governing vibration propagation. Low-stiffness (soft) railpads are effective in attenuating high-frequency vibrations; however, they may lead to increased rail deflections, enhanced low-frequency vibration components, and potential long-term maintenance concerns. In contrast, high-stiffness railpads restrict rail deflections but facilitate greater transmission of vibration energy to the supporting structure and surrounding ground, thereby increasing environmental vibration impacts. An intermediate (optimal) stiffness range is identified, providing a balance between vibration mitigation performance and structural integrity requirements. Overall, the findings offer practical insights for railpad selection by explicitly demonstrating the trade-offs associated with extreme stiffness values and emphasizing the need to align railpad properties with operational conditions. The proposed modeling framework serves as an effective decision-support tool for the design of vibration-sensitive railway infrastructure.
To be presented in the 32nd International Congress on Sound and Vibration (ICSV32) in Istanbul, Türkiye, from 5 to 10 July 2026: The 32nd International Congress on Sound and Vibration
