Dynamics Model Of Leaf-spring Based On Solid Mesh And Its Application

The non-linear factors, such as contact nonlinearity and geometric nonlinearity,existing in leaf springs multiply difficulties in its model establish and performanceanalysis. Based on nonlinearity contact dynamics theories and CAD/CAEtechnologies, this paper proposes a method for this kind of problem.Firstly, according to the nonlinearity contact dynamics theory, this paperanalyzed the contact and friction between spring-leaves and proposed a modelingmethod based on the contact analysis between spring-leaves. Combined the finiteelement method with the multi-body dynamics, the contact and friction parameterswere obtained by introducing the small-population genetic algorithm. Thenestablished a leaf spring’s multi-body dynamics model for a heavy truck.Secondly, the stiffness characteristic simulation analysis was implemented to theleaf spring. According to the conditions in staging testing for vehicle’s leaf spring,the stiffness value was obtained after a stiffness characteristic test for a heavy truck’sbalanced suspension. The feasibility and the credibility of this model are proved, bycomparing the testing results and the simulation results of the case, which showedthat the testing curve accords with simulation curve basically and its relatively erroris0.79%. When compared to discrete beam element model, the model presented inthis paper proved to have a better accuracy.Thirdly, a simplified rigid-flexible multi-body dynamics model for a heavy truckwas set up, in which the leaf springs were modeled by flexible bodies. The model’sride performance under pulse input and static roll stability were simulated. Then thesame items were tested in a road testing for the data and curves in real workingcondition. Comparison between simulation results and testing results indicated thatthe results were valid, because the testing curve accorded with simulation curvebasically. Besides, the maximum relatively error in ride performance under pulseinput analysis was9.79%and the maximum relatively error in static roll stabilityanalysis was4.75%. Therefore, it is proved that the modeling method presented inthis paper is accurate and effective.