EVALUATION OF SHOCK ABSORBER TESTING METHODOLOGY THROUGH NUMERICAL SIMULATION
Guilherme Barbosa Lima1; Bruna Luiza Nolli1; Ana Thais Almeida de Melo1
1 UFMG
doi:10.20906/CPS/COB-2015-0407
Resumo
Shock absorbers are used in oscillatory systems in order to control vibration, dissipating the motion energy. To predict shock absorbers behavior in the system, it is necessary to know its characteristics. However, the details of the shock absorber setup are usually restricted to the manufacturer, leading to the need of testing the equipment. Previous studies described test methodologies in which it is measured the displacement, velocity and reaction forces during its actuation with a cyclical test machine. This testing main goal is to decompose the measured force in the theoretical portions, isolating the interest variables. Some variables are velocity dependent and others are only displacement dependent, requiring a proper definition and control of the test velocity to allow the isolation of force components. In this study an experimental test methodology was evaluated through a numerical simulation of a shock absorber's simplified model, in order to determine the tests boundary conditions that allow the measured force decomposition. The model was developed for a hydro-pneumatic shock absorber (viscous damping and gas charged), representing the theoretical forces acting on it: damping, stiffness and Coulomb friction. The simulation results had a good agreement with the theoretical data and revealed the ideal testing boundary conditions, defining mainly the actuating velocity along shock absorber axis.
Palavras-chave: shock absrber; testing methodology; numerical simulation