Preparation and Dynamic Characterization of Magneto-Rheological Elastomers

Abstract

The civil engineering structures are prone to earthquakes, particularly the high rise buildings and bridges. With the development of large-scale civil engineering structures, the need for safety of these structures has also increased significantly. The most crucial factor in this regard is the earthquake. Various efforts have been made in the past to make large-scale civil engineering structures safe against earthquakes. One of the techniques being used for the seismic protection of structures is the base isolation. This technique is helpful in improving the seismic response of the large-scale structures, but it has limitations of functionality in near-field and far-field earthquakes. Thus, there is a need to improve the effective range of base isolation systems to cater to the wide range of earthquake excitations. This research introduces the concept of using Magneto-Rheological Elastomers (MREs) as a potential replacement of traditional rubber pads in base isolation systems. MREs is a class of smart materials whose stiffness can be varied by changing the applied magnetic field. In this study, MREs were prepared using 20%, 30% and 40% content of iron powder in silicon rubber. SEM was performed to study the microstructure of MREs. Dynamic fatigue tests were performed on the samples by varying the frequency and amplitude of loading. Moreover, the effect of the magnetic field was also studied. Maximum MR Effect and Strain Rate Effect of 29.72% and 43.45% respectively was observed for 40% iron content samples. Moreover, it was also observed that MR Effect is mainly dependent on the magnetic field whereas Strain Rate Effect is controlled by the frequency of loading.