Calculation of the amplitude-frequency characteristics vehicle vibrations taking into account the inelastic resistances in rubber vibration isolators
One of the output characteristics of rubber and rubber-metal vibration protection elements is the elasticity characteristic, which is a graphical representation in the "force-strain" coordinates of the functional dependence of the load acting on the element on the deformation caused by it when the load changes, both during the loading of the element and during its unloading. The characteristic in its clear form (in the form of the area of a closed loop) reflects the energy lost during the deformation of the element from the action of inelastic resistance forces (damping ability), and the slope of the midline of the characteristic reflects the elastic properties of the element. The model of the damping capacity of a rubber or rubber-metal vibration protection element is constructed by analogy with the elliptical-power model of the absorbing capacity of a pneumatic tire. To evaluate the proposed model, an oscillatory system equivalent to a "flat" car with a set engine mass was selected. The Runge-Kutta numerical method was chosen to solve the system of differential equations describing the vertical mass fluctuations of the car. The solution of the equations with the vibrational parameters of the GAZ-3102 passenger car and the vibration isolator (engine cushion) showed that the introduction of an elliptical-power model of the vibration isolator into the equations of mass motion leads to a decrease in the amplitudes of vibrations in the low-frequency resonance zone and, consequently, reduces the level of vibration load of the engine from external influences (uneven roads).