Étude et simulation des interactions entre particules dans un fluide magnétorhéologique
|Abstract:||Because of their great potential in mechanical design, magnetorheological fluids have been the subject of a lot of research during the last decade. Although they are already used in some semi-active dampers, their use in other promising technologies such as magnetorheological clutches remains not usual. The main reason for this lack of representation in clutch technologies is the relatively low shear stress transmission capability of these fluids. As a solution, some researchers proposed the application of a compressive stress on the fluid layer while maintaining a magnetic field. As a result, the shear stress transmission capability increases significantly. This effect has been called the Squeeze-Strengthen effect. This effect focuses on the significant interactions between the ferromagnetic particles present in the fluid. This master thesis proposes a global approach to study and model the interactions between particles in magnetorheological fluids. First, experiments are performed to study the Squeeze-Strengthen effect in the context of clutch technologies. The tests have shown that shear stress transmission capacity can be easily increased more than ten times the initial capacity without compression. Then, a numerical model based on the discrete elements method applied to the magnetorheological fluids is proposed. This simulation allows the determination of the state of forces on each particle considered in the model. Some qualitative observations of the particle structure can be made from this simulation. Finally, the bases of a mathematical model of continuum mechanics applied to the magnetorheological fluids are posed. In order to take the particle interactions into account, the assumption of a micro polar medium is made. An homogenization technique is proposed as a way to use the information obtained from the numerical simulations and the experimental investigations in order to obtain the rheologic behaviour laws.|
|Document Type:||Mémoire de maîtrise|
|Open Access Date:||19 April 2018|
|Collection:||Thèses et mémoires|
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