The objective is to perform a series of simulations using a simulation model of a semitrailer combination with validated input parameters based on the results of real vehicle dynamics driving tests, in order to draw conclusions on the impact of load placement and different axle spacings (with C2 axle raised (inactive) and lowered (active)) on driving stability. The mathematical simulation model on which the analyses are based has been previously developed.

Load placement has a significant impact on the stability and axle loads of truck trains, so in order to ensure road safety and to comply with the permitted axle load requirements, a specific combination of vehicle combination and load was investigated.

The test tool used was PC-Crash 12.1 simulation software, in which the load was defined as a multi-mass body. During the simulations, we ran the vehicle assembly on a standard dual lane change track and a circular curve track.

In the simulation, we changed two main parameters. One parameter is the positioning of the load, i.e. the change of the centre of gravity of the load along the longitudinal axis in three different positions. The other parameter is the change in the theoretical axle distance of the semi-trailer resulting from the position of the C1 axle, which was created by operating and lifting the C1 axle.