Evaluation of an innovative composite railway sleeper for a narrow-gauge track under static load

This paper introduces an innovative composite railway sleeper with an optimal material usage for a narrow-gauge railway track under static loading condition. The composite sleeper is designed using sandwich panels that were bonded and coated with epoxy polymer matrix. The sleeper's optimized shape was obtained using topology optimization. The vertical deflection and sleeper-ballast contact pressure of the optimized sleeper were analyzed by finite-element simulation and compared with a traditional timber sleeper. Prototype sleepers were then manufactured and their performance was evaluated experimentally. Results showed that the optimal sleeper shape only needs 50% volume of materials required for a standard rectangular timber sleeper. The performance of the optimal sleeper satisfactorily met the Australian standard requirements and was very similar to a timber sleeper indicating the high potential of this sleeper technology to replace the existing timber sleepers. This new sleeper is currently being tested in the Queensland Rail network as part of their sleeper maintenance program.