Rail pad, or railway rubber pad, is a material available to decrease the vibration transmitted from the rails to the sleeper or subgrade.
What is the stiffness of the rail pad?
Rail pad stiffness varies widely, from soft pads < 80 kN/mm to hard ones > 150 kN/mm, measured as resistance to deformation, but it's nonlinear, changing with load (amplitude) and frequency, with materials like EPDM, TPE, and EVA having different ranges (e.g., EPDM ~85 kN/mm, TPE ~139 kN/mm) and high-frequency stiffness often differing from static tests.
| 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. |
How does pad stiffness affect the durability of the track system?
Rail pad stiffness significantly impacts track durability: softer pads generally reduce dynamic forces, lowering stress on components, preventing ballast breakage, and extending fatigue life, while stiffer pads can increase vibration, mean stress on fasteners (like clips), and plastic strain, potentially shortening component life but restricting rail movement. The ideal stiffness balances load distribution, vibration damping, and component stress, with optimized pads (often softer with good damping) reducing degradation, improving track quality, and lowering maintenance needs.
Effects of Soft Rail Pads (Lower Stiffness)
- Reduces Stress & Wear: Spreads loads better, decreasing contact stress on ballast and sleepers, preventing breakage and permanent deformation.
- Dampens Vibrations: Absorbs impact, reducing high-frequency vibrations and accelerations in the track structure.
- Improves Fatigue Life: Lowers stress cycles on fasteners, significantly extending the fatigue life of components like clips.
- Reduces Rail Corrugation: Softer under-sleeper pads (USPs) are effective at reducing rail corrugation, a major wear issue, especially in curves.
- Potential Drawback: Can lead to increased rail displacement and potentially higher noise if damping isn't sufficient.
Effects of Stiff Rail Pads (Higher Stiffness)
- Restricts Rail Movement: Tightly couples the rail to the sleeper, limiting rail vibration but increasing sleeper vibration.
- Increases Component Stress: Intensifies mean stress and plastic strain in clips, shortening their fatigue life.
- Can Cause Noise: Stiff pads might transmit more noise if not paired with other damping elements.
- Better for Specific Issues: In some designs (like two-stage systems), a stiffer upper pad helps control rolling noise.
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.