Estudo de uma bancada de vibrações para análise da resposta dinâmica de uma suspensão automotiva

Abstract

This work presents the study of a vibration test bench to analyze the dynamic response of an automotive suspension. The vehicular dynamics of a car can be represented by analyzing a single degree of freedom suspension model, and the suspension system is composed of a suspended mass interconnected to the primary suspension, connected to the non-suspended mass of the axle. Thus, by performing numerical simulations it is possible to analyze the influence that the main parameters could have on the suspension system so that adjustments can be made. The test bench can be used as a teaching tool since it is possible to visualize and understand the necessary physical phenomenon with the suspension system when its dynamic characteristics are changed. For the development of the bench, a double A suspension model was used, as well as the shock absorber, a tire, and a wheel of an off-road model aircraft cart, which were harmonically excited through the profile of a projected shaft following simple motion equations, coupled to a shaft and having a reduction system using a pulley and V-belt, driven by an electric motor. The design of all system components was developed. After that, the bench was modeled as a system having a single degree of freedom being excited harmonically. A numerical model was also developed, enabling simulations to be carried out to understand and analyze the dynamic characteristics of the system, and to verify the influence generated when its main characteristics were changed, such as, by adding mass, changing the constants damping and spring, as well as initial conditions. By modifying the system parameters, it is possible to verify the existence of the phenomenon of beating, resonance, as well as impulse response of the system. In addition, through the bench, it is possible to demonstrate to the students of the Mechanical Engineering course at the Universidade Tecnológica Federal do Paraná - Pato Branco campus some of the concepts seen in the classroom in the vibration discipline in a practical way. Thus, through the bench, it is possible to verify the main dynamic characteristics present in a vehicle's suspension system.