Vertical and Horizontal Vibration Response for Corrugated Track Curves Supported on Steel and PY-Type Concrete Sleepers

A modal method experiment is conducted to study the dynamic difference in rails supported on PY-type concrete and steel sleepers. Frequency Response Functions (FRFs) for rails supported on both types of sleepers are studied and correlated with one another. Vibration response of the rails is studied for two positions; mid-span and on top of sleeper point. Resonance modes of interest are excited in a mid-frequency range of 0 – 500 Hz. These occur in the vertical direction for rail on PY-type concrete sleepers and in the horizontal direction for rail on steel sleepers. When the entire response window is considered, the FRFs prove resonances of the rail supported on steel sleepers to be heavily damped than those of rail supported on PY-type concrete sleepers. In contrast, accelerance (frequency-dependent acceleration of a point divided by the force excitation) is slightly higher for rail on steel sleepers. Explanation to this may be that the rail weighs 9 Kg less (per meter length) than rail on PY-type concrete sleepers. Different parts of the response FRF may be stiffness and some mass dominated. Vibration response in a horizontal direction is higher and more pronounced than the vertical for rails supported on both types of sleepers and on both positions of the rail.