Active and semi-active suspensions have been evaluated for application on tractor/semi-trailer trucks using a pitch plane simulation model called "VESYM". VESYM is a fully non-linear time domain simulation model. This paper reviews the effect of alternative heavy truck suspensions on pavement damage by using the flexible pavement simulation program "VESYS". It is shown that by estimating axle tire force and using this signal to modulate a semi-active shock absorber that significant reduction in pavement degradation can be achieved.

In this paper, the dynamic effects of heavy vehicle suspensions are investigated by analyzing parametric studies performed using previously developed simulation tools. In particular, the truck simulation package, VESYM, and the flexible pavement simulation package. VESYS, are used to look at the influence of alternative suspension types, e.g., walking beam, leaf spring/short rocker, air spring and semi-active shock absorbers on pavement response.

The intent of the study is to determine differences between suspension types as well as to look at the sensitivity to parameter changes and optimization within a particular suspension type.

The simulation results indicate that substantial improvements in pavement longevity may be possible by careful suspension selection and optimization.