Investigation of the Influence of the Centre of Gravity Position on the Course of Vehicle Rollover

Rollover crashes belong to the most danger type of road accidents. Particularly vehicles with a high situated center of gravity are exposed to this type of accidents. The basic measure of vehicle resistance to rollover is Static Stability Factor SST, i.e. the ratio of half the track width to the height of the center of gravity. In the quasi-static rollover limit it is assumed that the SST should not be less than the tire-to-road friction coefficient. This follows from the assumption that the side skid is less dangerous than the rollover. Most of the passenger cars are designed in order to prevent the rollover on flat surface with normal friction. However from several reports it is known that the quasi-static rollover limit can be not met in the case of vehicles with the high center of gravity position (in relation to the tread): heavy trucks, delivery vans or busses, especially high-floor coaches and double-deckers. Also other cars especially, very trendy at present, SUVs and trucks could also undergo the rolling over when the tire-to-road friction coefficient would be extremely high, namely its value would exceed 1 or more. The rollover can happen on a flat surface also when the height of the centre of gravity is higher then the height assumed by the designers. In the paper the method of calculation of the course of rollover in time domain is described and it is investigated the influence of the height the centre of gravity on the increase of the rollover angle velocity. The conducted calculations show that during rollover the rotation angle of the vehicle increases progressively. It can be noted that the higher the vehicle centre of gravity is located, the faster the rotation angle increases. On the basis of calculation results it is discussed whether the drive has a chance to counteract the rollover of the vehicle. It is shown, that in a few first tenth parts of the second the angle of the rotation is small enough that it gives the driver a chance to correct the movement of the car using the steering wheel or by reducing speed, even when the rollover process has already begun.

• Record URL:
  http://www-esv.nhtsa.dot.gov/Proceedings/24/isv7/main.htm
• Corporate Authors:

  National Highway Traffic Safety Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Reński, Andrzej
• Conference:
  • 24th International Technical Conference on the Enhanced Safety of Vehicles (ESV)
  • Location: Gothenburg , Sweden
  • Date: 2015-6-8 to 2015-6-11
• Publication Date: 2015

Language

• English

Media Info

• Media Type: Digital/other
• Features: Appendices; Figures; References; Tables;
• Pagination: 12p
• Monograph Title: 24th International Technical Conference on the Enhanced Safety of Vehicles (ESV): Traffic Safety Through Integrated Technologies

Subject/Index Terms

• TRT Terms: Buses; Calculation; Center of gravity; Crash phase; Drivers; Heavy duty trucks; Ratios; Rollover crashes; Rotation; Sport utility vehicles; Stability (Mechanics); Vans
• Subject Areas: Highways; Safety and Human Factors; Vehicles and Equipment; I91: Vehicle Design and Safety;

Filing Info

• Accession Number: 01572024
• Record Type: Publication
• Report/Paper Numbers: 15-0153
• Files: TRIS, ATRI, USDOT
• Created Date: Jul 31 2015 5:59PM