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Smart materials, such as electrorheological (ER) and magnetorheological (MR) fluids, have been proven to be tuneable in terms of their mechanical properties and to be valuable in the application of vibration suppression. However, MR fluid has such disadvantages as sedimentation of particles and complexity of the magnetic field design. ER fluid is also difficult to apply for practical uses due to the limitation of the yield stress. Giant electrorheological (GER) fluid represented a large break-through in the yield stress with the ability to improve the performance of the mechanical properties. This advance facilitates the practical use of rheological fluids in the field of vibration suppression. In this paper, a GER fluid damper composed of multiple electrodes working in shear mode is proposed. When the GER fluid damper functions in shear mode, it simplifies the structural design and has the advantage of producing a high damping force with a low stiffness effect, which is beneficial for energy dissipation without influencing other mechanical performance parameters. The dynamic mechanical properties are measured experimentally. Based on this proposed damper, a mathematical model composed of the hysteretic formula, Stribeck effect and viscous formula is built, and the parameters are identified by the ant colony algorithm according to the experimental results. This model can describe both the hysteresis in the velocity-force curves and the force mutation in the low velocity region. Next, identified parameters are regressed, and the model is validated. Additionally, experiments on vibration suppression are conducted to verify the practical value of the GER fluid damper. The results illustrate that the vibration is significantly suppressed with a reduction of 91.03% by using the GER fluid damper, and the tuneable range reaches 43.8%.

When permanent magnets are surrounded by ferromagnetic materials, the magnetic field lines are rerouted in the air gap between them, which provides an approach for the optimum design of the eddy current damper. To improve the conventional tubular eddy current damper design, an enhanced eddy current damper with a ferromagnetic shaft and a ferromagnetic layer is successfully developed in this study. It is passive, cost-efficient and reliable, significantly boosting the damping effect without occupying extra space. To explore the benefits of the ferromagnetic material, analytical models of the magnetic field distributions are derived to estimate the damping coefficient. In addition, the ferromagnetic material configuration and dimensions of the proposed eddy current damper are optimized for better vibration suppression. The experiment results agree reasonably well with the theoretical models and finite element predictions, and demonstrate the effectiveness and efficiency of this innovative design, which realizes a remarkable improvement in the damping coefficient, from 70.5 N • s m −1 to 143.2 N • s m −1 .