Testing of heavy vehicle suspensions : proof-of-concept : ‘white-noisy road test’ and ‘pipe test’ to determine heavy vehicle suspension parameters.

In Australia the ability for heavy vehicles to carry higher mass limit (HML) loadings on their axle groups is conditional on them having road friendly suspensions (RFS) installed. To characterise any system one technique is to apply an input signal to that system and measure the response of the system output. Such input signals are sometimes called forcing functions. Two forcing function methods are covered in the conceptual framework outlined in this paper. By analysing the output signals of transducers attached to the trucks suspension components the characteristic values of damping ratio and the natural frequency of body-to-axle bounce may be derived. This document sets out the processes (and proves the previously-assumed concepts contained within this framework) for low-cost in-service suspension testing of heavy vehicles. It then shows how those assumptions were validated against empirical testing data. Theory behind previous work is expanded leading to its practical application to heavy vehicle suspension testing. Analysis tools and techniques are provided and discussed. (Author/publisher) For the covering entry of this conference, please see ITRD abstract no. E214133.