Effect of obstacles in the road profile on the dynamic response of a vehicle

Abstract

The simulation study is aimed at explaining the effect of large obstacles (bumps and potholes) appearing on a road surface on the response of a vehicle passing the obstacle. For the tyre representation, the simplest point-follower model was used. Only the random obstacle modelled by cosine waves of variable height and constant height-to-length ratio was applied. For the traversing vehicle, two models were considered: a planar model of a personal car with a driver and one passenger, and a planar model of a three-axle truck. Vertical accelerations acting on the travelling people and dynamic tyre forces were estimated. In the first part of this paper, the dependences of the extreme values of the vehicle responses when passing an isolated obstacle on the obstacle height and the travel speed were evaluated. In the second part of this paper, the r.m.s. values of the same quantities were evaluated when the vehicle passes a road section with a standard pure random profile on which a number of randomly distributed obstacles were superimposed. The dependences of all quantities in question on the ‘obstacle density’ and on the travel speed were estimated.