A numerical analysis of a double multi-leaf spring model

The use of a double spring in a vehicle suspension as a combination of elastic components of characteristics which are approximate to linear ones gives a nonlinear suspension nature, which should approximately meet the criterion of car motion smoothness connected with keeping the frequency of the free vibrations of the a motorcar body in the range of l - 2 Hz, in the whole range of load changes (cargo) [see references 8, 10]. The subject of considerations is a prototypical double spring that consists of a four-leaf main spring and a two-leaf auxiliary spring and is meant for the family of motor trucks (delivery trucks) of a total mass of about 3,51. The presence of a clearance between the main spring and the auxiliary spring is the specificity of the aforementioned structural solution. In the present study, there are presented different variants of FEM numericał models ofa double spring as well as selected aspects of their applications at the stage of the research on the displacements and deformations of selected structural components. The structures ofa two-dimensional beam model, a three-dimensional shell model and a solid model of a double spring are discussed. Moreover, the study discusses different approaches in the modelling of the effect of contact between particular leaves and their influence on analysis results. Selected model tests results were compared with experimental research results.