Application of nonlinear dry friction force of heavy haul freight car using equivalent linearization method

A new equivalent linearization method based on describing function approach was presented to do mathematical treatment on nonlinear dry friction shock absorber of heavy haul freight car, and respectively, the vertical and lateral non-linear friction force between the wedge and bolster were equivalent to the vertical and lateral linear damper, and after equivalent linearization, the dynamic performance analysis of linear vehicle model is carried out and compared with the corresponding dynamic results of nonlinear model, furthermore, the equivalent linearization model was applied to dynamic response analysis of heavy haul freight carthe existing bridge coupling system to study the effect of vibration of the existing bridge on dynamic performance of heavy haul freight car. The results show that, within a certain error range, equivalent linear model of nonlinear dry friction force in freight car based on describing function approach is correct, and can replace the complicated nonlinear model to study the dynamic response of freight car-existing bridge coupling, and it provides an effective way to analyze and predict dynamics performance of heavy haul freight car-existing bridge coupling system.