Suspension Components

An examination is made of the force developing characteristics of road vehicle leaf springs under realistic broad band random loading conditions. A program of laboratory measurements on two vehicle springs is described. The measured responses are compared with digital computer simulations of the springs which use empirical descriptions of their low frequency (quasi-static) behaviour. It is concluded that two different empirical descriptions can be used for predicting accurately the forces developed by typical road vehicle leaf springs to at least three times the highest frequency of major excitation. Both require a detailed knowledge of the small amplitude, low frequency behaviour of the springs at the static load of interest. The popular Coulomb friction model of leaf spring behaviour is shown to be inaccurate throughout the entire frequency range.