Mechanical Performance and Dynamic Characteristics of a Novel Bamboo-Plywood Composite Railway Sleeper

Abstract

In recent years, the railway industry has increasingly focused on using recycled and composite materials for construction, with a particular interest in bamboo due to its status as a highly renewable natural resource. Recognized not only for its durability and strength, bamboo is also valued for its sustainability, low embodied energy, and ease of handling. This paper aims to investigate the mechanical and dynamic characteristics of a novel bamboo-plywood composite sleeper (BCS), conducting tests such as three-point bending, four-point bending, modal analysis, and wheel drop tests. This study compares the mechanical performance of BCSs with that of timber sleepers (TSs) and concrete sleepers (CSs). The bending moment test results reveal that BCSs possess a higher bearing capacity than CSs, achieving up to 300 kN, and exhibit ductility comparable to TSs, with bending stiffness intermediate between the two. The DIC results indicate that BCSs experience shear failure following high elastic bending, with DIC observations showing interlayer cracks in the middle area of the cross-section under shear stress, leading to sleeper fracture and expansion. Modal testing confirms that the bending stiffness of BCSs lies between that of CSs and TSs, and their damping ratio is similar to that of CSs, suggesting that the vibration attenuation of BCSs is comparable to that of CSs. The vibration characteristics of BCSs reveal that the vibration peak at the seat is lower than that of CSs, while the vibration peak in the center area is more significant. Furthermore, frequency domain analysis indicates that BCSs display higher or comparable vibration resistance and have the potential to effectively reduce vibration compared to CSs. The integration of bamboo into railway sleeper design not only promotes environmental sustainability but also paves the way for the development of next-generation railway infrastructure solutions.

Keywords: Bamboo scrimber, composite sleeper, bending test, Digital Image Correlation, impact test, vibration resistance