Plataforma de testes dinâmicos para amortecedores magneto-reológicos e representação através de modelos de histerese

Abstract

The mechanical damper is a device generally used to protect the system to which it is attached, to minimize the effects of vibrations that may cause damage. Dampers can be classified into three forms: passive dampers, active dampers, and semi-active dampers. In the latter type, we have shock absorbers that use magnetorheological fluid, and they have attracted the attention of researchers due to their high reliability and modest cost. Magneto-rheological fluids can modify their mechanical properties using a control signal. However, knowing the dynamics of this type of device is a difficult task due to its hysterical behavior. To obtain the experimental data shown in this dissertation, a test platform was built in which the magneto-rheological damper is coupled to a table and excited with different frequencies and displacements. The data obtained were used to calculate the parameters of a mathematical model, known as the Dahl model, capable of describing the hysteresis behavior of the shock absorber. The Dahl model was used in this work in association with a two-story building structure model. The objective was to assess the behavior of the building’s structure when subjected to an earthquake. This simulation indicates that the use of MR shock absorber in structures can minimize the physical damage caused to the structure by an eventual earthquake.