Rollover Study of a Heavy Truck Combination with Two Different Semi-Trailer Suspension Configurations 2014-36-0025

Brazil presents a very diverse road and traffic conditions and due to several factors the number of truck accidents is very high. Inside truck accidents group, the one that causes the highest number of losses and fatalities is the rollover crash and understanding rollover dynamics is very important to prevent such events.

The diversity of cargo vehicles arrangements requires a detailed study regarding the dynamic behavior these vehicle combinations in order to increase operation safety. The same tractor unit can be used with different types and numbers of trailers and/or semi-trailers, each one with different suspension configurations. These truck combinations have distinct dynamic performances that need evaluation. In this sense, this work presents a first phase study on the dynamic behavior of different types of cargo vehicle configuration. A 6×2 tractor is combined with a two distinct grain semi-trailer with different types of suspension: pneumatic and leaf spring. The study is conducted in order to verify the difference in dynamic behavior and the resulting stability of the two configurations in different conditions of speed and maneuvers.

The study was conducted with simulation models developed within TruckSim® simulation software, with calibrated data from tests previously performed. The simulations were carried out according to the main standards tests used for this kind of analysis - Slalom, Double Lane Change (DLC) and Step Steer maneuvers, to check the directional behavior and limit rollover of both truck combinations. The simulations showed significant changes with respect to the behavior of the combinations, depending on the type of used suspension, especially with regard to the rollover tendency. Different types of combinations with the same tractor show different lateral load transfer, not only depending on the arrangements and quantity of suspension axles, but also due to the different possible locations of loads. These results are interesting for a better understanding of the lateral dynamics of different cargo vehicle compositions, in order to establish better safety margins against the rollover threshold and to accomplish future setups for the electronic control stability systems of combination trucks.