Use of nonlinear asymmetrical shock absorber to improve comfort on passenger vehicles

Study of forced vibrations of the Kelvin-Voigt model with an asymmetric spring

“…4, 6, and 9) decrease the amplitude of vibrations at the basic frequency (the driving force frequency) due to the appearance of superharmonic vibrations and, as a consequence, the energy pumping to higher frequencies, which decreases in the amplitude of vibrations at the frequency of the external perturbing action, which is required for several types of vibration dampers. As examples of such vibration dampers, most of which are based on the systems described by the Duffing equation, we note the vibration dampers used in automobile industry [9,10], the dampers of torsional vibrations of ship shafts [11], and the dampers of anharmonic shock actions [12].…”

“…The special characteristics of the behavior of such systems, as well as of similar nonlinear systems [7], which are mainly related to energy pumping from the frequencies of the perturbing action to other frequencies, and, as a consequence, the appearance of superharmonic vibrations open wide prospects of their application for efficient damping of vibrations at the frequency of the external action [9,10]. Several examples of vibration dampers with nonlinear characteristics, including those whose springs have different moduli of elasticity, which are used to damp the anharmonic vibrations generated by the ship shaft whipping and some types of vibrations are considered in [11,12].…”

A methodology for calculating the passenger comfort benefits of railway travel

“…A Delphi-AHP method was used to determine the weight for each factor; then, the experiment was designed to test and verify correctness and feasibility of the passenger comfort evaluation process. Silveira et al [28] compared two different types of shock absorbers' behavior, symmetrical (linear) and asymmetrical (nonlinear), which were used on passenger vehicles. The final results showed that the asymmetrical system with nonlinear characteristics tends to have a smoother and more progressive performance, for both vertical and angular movements.…”

Contribution of electrical parameters on the dynamical behaviour of a nonlinear electromagnetic damper

“…Hence, it is expected that the resistance parameter has direct influence on the resulting mechanical damping action. The analysis of the linear model helps the understanding of the correlation between electrical resistance and mechanical damp- [18], which also resulted in the values related to the magnetic field and coil. All simulations were performed using a 4th order Runge-Kutta method with step of 0.01 s. Figure 3 shows the maximum displacement (x 1 ) of the linear system (8) as function of the excitation frequency ( f ex = ω ex /2π), for four values of R, and using C = 1,400 × 10 −6 F. With R = 0.824634 Ω, there are two resonance peaks at 1.25 Hz and 7.72 Hz.…”

“…Based on an application of a vibration absorber for vehicles, the stability and general behaviour of the electromechanical system is investigated. A conventional model of a vehicle suspension system is divided in two subsystems, one comprising the tyre, wheel, brake discs and upright, called unsuspended, or unsprung, system, and another comprising the proper suspension system and the whole chassis, called suspended, or sprung, system [18]. For a fourwheeled vehicle, the mass supported by each corner is about a quarter of the total mass.…”