Rail pads are elastic polyurethane mats which are interposed between steel rails and railway sleepers to protect the sleeper top from wearing and impacting.
The starting stiffness of a rail pad is designed to not be high so that their relative deformation under the spring clip toe loads is greatly substantial. In this way, it can guarantees the rail pad maintaining in close contact with the rail despite of any vertical movements of the latter. In addition, the reason why rail pads made up of rubber or plastic is to dampen the shocks of vibration of a passing train.
How is the vibration damping effect of rail pads evaluated?
Rail pad vibration damping is evaluated using lab tests like hammer impacts (drop weight) and frequency response analysis (e.g., sine sweep) to find the damping ratio (ζ), often combined with Finite Element Modeling (FEM) for prediction, analyzing acceleration data in time/frequency domains, and measuring vibration decay or transmission loss at different frequencies (1-200 Hz) to see how much energy is absorbed.
Key Metrics:
Damping Ratio (ζ): The fundamental measure of energy dissipation (ratio of actual damping to critical damping).
Acceleration Reduction: Measured in dB, showing how much acceleration (vibration) is reduced.
Band Gaps: Frequency ranges where vibration is effectively blocked, determined by FEM and analysis.
What are the technical parameters of a railway pad?
Railway pad technical parameters focus on mechanical properties (stiffness, hardness, strength), material composition (rubber, EVA, HDPE), dimensions, and environmental resistance, all crucial for dampening vibration, reducing wear, ensuring load distribution, and improving passenger comfort under dynamic train loads. Key metrics include stiffness (KN/mm), Shore Hardness, Tensile Strength, Elongation, and resistance to heat, cold, UV, and oil.
Key Technical Parameters
- Stiffness (Load-Deflection): How much force it takes to deform the pad, crucial for dynamic response; often specified with initial low stiffness for contact and higher stiffness under load.
- Hardness: Measured by Shore A (e.g., 72-80°), indicates resistance to indentation.
- Tensile Strength: Resistance to breaking under tension (e.g., ≥12.5 MPa).
- Elongation: Percentage of stretch before breaking (e.g., >250%).
- Density: Material mass per volume (e.g., 0.95-0.98 g/cm³).
- Insulation Resistance: Ability to resist electrical current (e.g., ≥1×10¹⁰ Ω).
| Raw Material | Rubber, EVA, TPEE, HDPE |
| Standard | UIC, AREMA, TB/T2626-95 |
| Application | 43kg/m, 50kg/m, 60kg/m, 75kg/m,115RE, UIC54, UIC60, S49 |
| Model number | 43-7-7, 43-10-7, 50-7-9, 50-10-9, 60-10-17, 60-12-17 |
| Operating temperature | -50~70 degrees |
| Certificate | MSDS, ROHS, REACH |
| Notes | They should be stored in a clean, ventilated place. Don't be in direct sunlight, and keep away from the heat source and chemical reagent. Don't touch the oil, organic solvent, and other chemicals. Banned exposure. |
As a professional rail fastener manufacturer, GNEE RAIL can produce various types of rubber rail pads with different materials, such as natural rubber, EVA, HDPE and so on. In railway fastening system, rubber rail pads are often installed between the rail tracks and the concrete railway sleepers.
