Faculty of Automotive and Transport Engineering
Book 4.2 - Sustainable and Intelligent Transport Systems, Technologies and Logistics
FRI-20.21-1-SITSTL-10
A QUASI-STATIC ANALYTICAL MODEL FOR VEHICLE AND TRAILER STABILITY ON RUTTED AND IRREGULAR ROAD SURFACES
Abstract: This article formulates an explicit quasi-static analytical model to assess the lateral stability of vehicle-trailer systems navigating rutted and uneven pavements. The model changes the quantifiable rut geometry (depth, breadth, wall angle, edge radius) and wind inputs into disruptive lateral forces and yaw moments. It then compares these to a capped, stiffness- and friction-limited restorative capacity to create a Stability Ratio (SR). The method connects field observation and calculation by putting first-principle force-moment balances into an easy-to-use Excel/VBA programme that engineers and auditors may use to quickly check things. Calibrated modifiers, such edge-radius smoothing and width attenuation, show how rounded rut edges and broad grooves make the rut "bite" less. Speed-aware restrictions stop the linear tyre law from over-predicting. The SR is seen as a capacity-to-demand factor with three decision bands: Stable (SR ≥ 2), Marginal (1 ≤ SR < 2), and Unstable (SR < 1). This helps with proactive risk triage and operational direction. Case reasoning shows how the geometry of the rut, crosswind, load location, and speed may all work together to cause trailer wobble and possible loss of control. This is in line with what we already know about dynamic amplification processes. The contribution is a defensible, auditable, and low-cost methodology to transform the state of the road surface into useful, measurable stability evaluations for infrastructure programmes and fleet operations.
Keywords: Roar rut, Road safety, Lateral stability, Irregular surface, Vehicle, Trailer, Quasi-static model
REFERENCES
- World Bank (2013). Report No: ICR287 MPLEMENTATION COMPLETION AND RESULTS REPORT (IBRD-48650) ON A LOAN IN THE AMOUNT OF EURO 90.0 MILLION (US$ 122.5 MILLION EQUIVALENT) TO THEREPUBLIC OF BULGARIAFOR AROAD INFRASTRUCTURE REHABILITATION PROJECT. December 16, 2013. https://documents1.worldbank.org/curated/en/247421468020658349/pdf/ICR2870P0998940C0disclosed0 40160140.pdf
- Melgaard, L., (2024). World Bank to Provide Strategic Advice on Bulgaria’s Roads Infrastructure. https://www.worldbank.org/en/news/press-release/2024/08/20/world-bank-to-provide-strategic-advice-on-bulgaria-s-roads-infrastructure
- Beresnevich, V., Viba, J., Kovals, E., Irbe, M. and Eiduks, M., (2024). Lateral sway motion of vehicle and trailer. In 23rd International Scientific Conference “Engineering for Rural Development”: proceedings:[Jelgava, Latvia], May 22-24, 2024 (Vol. 23, pp. 344-350).
- Hood, S., (2024). Truck Sway Accidents. Mc Gowan, Hood, Felder & Phillips LLC, September 3, 2024. https://www.mcgowanhood.com/2024/09/03/truck-sway-accidents/
- Sharma, T., He, Y., (2024). On Trade-Off Relationship between Static and Dynamic Lateral Stabilities of Articulated Heavy Vehicles. Designs 2024, 8, 103. https://doi.org/10.3390/designs8050103
- Hucho, W.H., (2015). Aerodynamics of Road Vehicles: From Fluid Mechanics to Vehicle Engineering. 5th Edition. Amsterdam: Elsevier, ISBN: 978-0768079777.
- Gillespie, T., (1992). Fundamentals of Vehicle Dynamics. Warrendale. SAE International, ISBN: 1- 56091-199-9.
- Wong, J., (2008). Theory of Ground Vehicles. 4<sup>th</sup> Edition. Wiley, ISBN: 978-0470170380.