Using similarity theory to analyze vehicle motion stability based on mobile model testing

The paper presents issues related to the use of a 1:5 scale mobile vehicle model for analyzing the motion stability of a truck. The paper presents the basic relationships of the Buckingham π theorem used to modify the mobile car model. The work performed and prepared to ensure similarity between the real vehicle and the mobile model is presented. Methods for determining individual model parameters are described. The presented work was created during the implementation of the NCBR research and development project no. PB 5478/B/T02/2011/40 titled “Assessment of the stability of a real vehicle based on mobile model testing”.

Loss of balance after the occurrence of excessive centrifugal force can lead to lateral skidding of the vehicle occurring on all wheels or to its rollover [2,3,4]. The second case, i.e., rolling over to the side, much more often concerns trucks with a high center of mass. Knowledge of this issue requires a series of studies and tests. Hence the interest in testing a vehicle on a scale that allows for the installation of measuring equipment and comparing the movement of the vehicle and the model. It should be noted that test studies of large-size vehicles are dangerous and expensive. Furthermore, introducing modifications to the vehicle is much more difficult than in the model. An additional advantage is the fact that during vehicle testing on a smaller scale, a vehicle testing track is not required, and a possible rollover of the model is not costly. For this reason, model research was undertaken, both on a physical scale model of the vehicle and using a computer model of the vehicle. (…)

Keywords: vehicle motion stability, mobile vehicle model, similarity – PDF file for download