Numerical Study on the Sensitive Wavelength and Amplitude Management of Track Irregularities in Monorail Systems

Track irregularity is one of the principal excitations that induces coupled vibrations in vehicle–bridge systems. Understanding the sensitive wavelength of track irregularities is critical for the evaluation and management of track conditions. Notably, existing studies generally focus on railway systems, but the characteristics of sensitive wavelengths in monorail systems are insufficiently understood. This study aims to investigate the influence of longitudinal level irregularity (LLI) on the dynamic response of the monorail tour transit system (MTTS), as well as the sensitive wavelength of LLI. First, a joint model was developed by integrating multi-body dynamics with the finite element method. The LLI utilized in the numerical mode was simulated by trigonometric functions with various frequencies (i.e., wavelengths) and amplitudes. The dynamic responses of monorail vehicles, including the wheel load reduction rate and vertical acceleration, were obtained and then used to evaluate track conditions. Results indicate that the dynamic responses of MTTS are mainly affected by the LLI with a wavelength of less than 5 m. In addition, it was found that, in the studied ranges, the sensitivity wavelength grows as the vehicle speed increases. Finally, the recommended value of LLI control under various track conditions was evaluated.

This creative work has been published under the Creative Commons Attribution 4.0 International (CC-BY 4.0) license which allows copying, and redistribution as well as adaptation of the original work provided appropriate credit is given to the original author and the conditions of the license are met.