Experimental Study on Dynamic Properties of a Recycled Composite Sleeper and Its Theoretical Model

• Main Authors: Zhenhang Zhao, Ying Gao, Chenghui Li
• Format: Article
• Language: English
• Published: MDPI AG 2021-12-01
• Series: Symmetry
• Subjects: composite sleeper; viscoelasticity; dynamic properties; frequency-dependent
• Online Access: https://www.mdpi.com/2073-8994/13/1/17

As a symmetrical structure in track system, the dynamic properties of recycled composite sleepers are important factors affecting the vibration characteristics of track structure. To study the viscoelastic dynamic properties of the composite sleeper, dynamic mechanical analysis (DMA) tests of a composite sleeper at −5 to 30 °C and 1–60 Hz were first carried out, and then the time-temperature superposition (TTS) and the Williams–Landel–Ferry (WLF) formula were used to predict the dynamic properties of a composite sleeper at a wider frequency range. Finally, the generalized Maxwell model was adopted to characterize the dynamic properties of the composite sleeper, which provides parameters and theoretical models for dynamic analysis. The research results show that the composite sleeper has obvious viscoelasticity. Its modulus is large at low temperature or high frequency. On the contrary, the modulus is small at high temperature or low frequency. Under the test conditions, its complex modulus ranges from 1500 to 2700 MPa. The loss factor is in the range of 0.08–0.13. Using the generalized Maxwell model (<i>n</i> = 4), which can better reflect the dynamic properties of the composite sleeper.