Benchmark trials of anti-vibration devices under random external loading

Anti-vibration seats are widely used in structures of modern mobile cars as one of the means of ensuring compliance with requirements of sanitary regulations regarding the level of vibrations at the driver’s seat. At that, the task of a justified choice of dynamic characteristics of the seat in accordance with parameters of external vibratory impact and specificities of dynamic system of a car is relevant. The structure of a modern anti-vibration seat is quite complex as in includes non-linear elastically damping elements. Therefore, it is necessary to experimentally determine characteristics of the seat as of a dynamic system when developing linear mathematical models.
The article is dedicated to experimental research of dynamic characteristics of Sibeco anti-vibration seat of the prospective T-11 industrial tractor of the Chelyabinsk Tractor Plant. V875-440-HBT 900 Combo electrodynamic vibration bench produced by LDS Company (England) was used for the research together with three-component accelerometers, LMS Scadas LAB data measurement system and LMS Test.Lab 13A software. In the result of the trials, an amplitude-frequency characteristic of the seat was obtained, based on which the own frequency and parameters of linearized mathematical model (mass, stiffness, viscous friction coefficient) were determined. Validity of determined characteristics is provided by repetition of the trials using the method of oscillation decrement under operation of the bench in the mode of impact loading. Moreover, trials were conducted under random loading, and certificate characteristics of the seat were obtained (SEAT transmission coefficient and the coefficient of transmission in the resonance zone).
The obtained characteristics were used during simulation of the tractor’s movement. It is shown that the most efficient way to reduce vibration load is changing its own frequency due to reduction of elastic behavior of the sprung seat system. The obtained dynamic results can be applied when modeling dynamics of vehicles equipped with analogous anti-vibration seat. The developed method can be applied during experimental research of anti-vibration devices.