Structural design of new mesh-type high-damping rail pad and comparative experimental study on the mechanical property with the traditional rail pads

Abstract

Commonly used rail pads (RPs) in urban rail transit fastening systems comprise prismatic and grooved rail pads (PRP and GRP). This research introduced novel mesh-type and mesh-type high-damping rail pads (NMTRP and MTHDRP) to mitigate RP’s stress and enhance damping efficiency while optimizing elastic material utilization. A finite element model (FEM) of the fastening system was established and validated through stiffness and hammering tests of the RPs. The FEA results revealed that the mesh-type RP offered advantages in uniform stress distribution and efficient material usage. The MTHDRP has a significantly lower stress level than the PRP and GRP because of the damping block, it will prolong the MTHDRP’s service life. Both NMTRP and MTHDRP displayed reduced static and dynamic stiffness in comparison to PRP and GRP. Notably, MTHDRP demonstrated the lowest dynamic-to-static stiffness ratio at 1.45, indicating superior dynamic stiffness retention capacity relative to the other three RPs. The hammering test found that the MTHDRP exhibited the highest damping ratio among the four RPs and consistently lower vibration amplitudes in the time and frequency domains at the rail, clip, track bed, and ground when compared to the other RPs. Furthermore, analysis of the 1/3 octave frequency band of the acceleration signal underscored MTHDRP’s excellence, with vibration levels reduced by 4.31, 4.37, 4.21, and 1.43 dB at the rail, clip, track bed, and ground, respectively, in comparison to PRP. These findings affirm the superior vibration reduction performance of MTHDRP relative to the other three RPs and underscore its potential for enhanced foundation protection when incorporated into rail systems.