Road authorities regard heavy vehicles (HVs) with road friendly suspensions (RFS) favourably. Accordingly, in Australia, RFS-equipped heavy vehicles (HVs) are allowed to carry more mass under certain conditions, such as the higher mass limits (HML) schemes, in each State. Two measurements used to show that heavy vehicle suspensions are road friendly are the damping ratio and the damped free vibration (natural) frequency. Normally these are found by expensive laboratory testing where a truck is mounted on a frame and subjected to calibrated jolts and vibrations. Two low-cost processes for testing heavy vehicle suspensions for in-service testing of RFS have been documented. They comprised methods where a truck was driven on typical roads and a method involving driving a heavy vehicle over a pipe. The signals induced by the on-road test were then analysed to derive the damped natural frequency of the body bounce. This paper describes the testing and results of an expanded testing programme and expands greatly on the results of previous test programmes. The expanded test programme comprised two measurement regimes made up of a combination of semi-permanent on-board systems and temporarily attached transducers. These systems recorded data during pipe tests, a stepdown test and on-road excitations. (a) For the covering entry of this conference, please see ITRD abstract no. E216058.
Abstract