Modelling and Simulation of Car Suspension with Linear and Nonlinear Spring

Abstract

AbstractIn this paper, a new approach is defined to change the linear stiffness of the spring element in the passive suspension system, instead of redefining the entire arrangement altogether. The linear cylindrical spring is replaced by a Nonlinear Conical spring, whose stiffness varies depending on the load-induced; and thus conical spring designs are studied and developed to fit in the application. The properties of this nonlinear spring are then imported into the car model using Combin39 Nonlinear Element in ANSYS, to check its response on vehicle dynamics such as bounce, roll, and pitch, under the road excitation of the speed bump, as compared to the linear rate spring working on the same range of vehicle loads. The car models are developed in ANSYS Workbench and MATLAB Simulink to compare with the analytical solution using the State-Space Model, for further validation. The results of Modal and Transient analysis showed some significant reduction in natural frequencies and amplitudes of sprung mass motions; thus concluding that conical springs do work and perform the best of both worlds, and fill the gap between passenger comfort and vehicle handling characteristics; without modifying the entire suspension arrangement.KeywordsCombin39 elementModal analysisNonlinear conical springTransient analysis