Experimental study on track irregularity of straddle-type monorail.

Area of Science:

• Engineering
• Transportation Systems
• Mechanical Vibrations

Background:

• Straddle-type monorail systems face design complexity due to higher speeds and gradients.
• Guideway surface irregularities are key excitation sources in vehicle-guideway interaction.
• Existing dynamic models often use generalized spectra due to limited specific monorail data.

Purpose of the Study:

• To characterize track irregularities specific to straddle-type monorail lines.
• To collect high-fidelity, real-world track irregularity data.
• To refine boundary conditions for dynamic modeling and improve operational performance.

Main Methods:

• Conducted field tests on a revenue-service straddle-type monorail line.
• Utilized dedicated onboard measurement equipment for data acquisition.
• Performed spectral analysis, comparing results to established railway and road spectra (e.g., ISO 8608).
• Quantitatively assessed and fitted vertical and lateral irregularity spectra using numerical methods.
• Categorized spectra into Class A (excellent) and Class B (poor) based on amplitude distributions.

Main Results:

• Measured spectral features of straddle-type monorail track irregularities.
• Proposed spectral fitting coefficients for Class A and Class B irregularity categories.
• Provided a quantitative assessment of vertical and lateral irregularities.

Conclusions:

• The study provides critical reference data for straddle-type monorail vehicle-guideway systems.
• Characterized spectral features offer improved inputs for dynamic design and optimization.
• Findings enhance the understanding of track irregularity impacts on monorail performance.