Mathematical modeling and nonlinear analysis of stiffness of double wishbone independent suspension

Suspension stiffness is a key parameter that affects vehicle ride comfort. Because the stiffness of the double wishbone independent suspension is nonlinear, it is difficult to accurately reflect the elastic characteristics of the suspension by using the traditional linear mathematical models. In this paper, a nonlinear mathematical model of the double wishbone independent suspension was established by using the method of kinematic analysis, the influence of rubber bushing stiffness and torsion bar load on suspension stiffness were analyzed quantitatively. The multibody dynamic model of suspension was established by using Adams software, and the error between simulation and theoretical calculation of the suspension stiffness is 0.19 % to 2.3 %. The suspension bench test was carried out and the error between the test and theoretical calculation of the stiffness is 0.5 % to 4.8 %. The simulation and test results verify that the nonlinear stiffness mathematical model can be used to accurately calculate the dynamic characteristics of suspension stiffness, the results provide theoretical basis and reference for accurate design of suspension stiffness.