Magnetorheological (MR) dampers have the ability to mitigate natural hazards for structures due to their high energy dissipation features with low power demand. This feature has made the MR damper one of the most popular semiactive damping devices. The present work validates the performance of a single-story reinforced concrete (RC) frame using a reduced scale 10 kN capacity multiple coil MR damper that has recently been developed by the authors. To conduct this test, MR fluid is synthesized and the proposed multicoil MR damper was designed and fabricated. Three RC frames were cast and tested using a loading frame with a capacity of 50 kN. This frame was subjected to earthquake excitation with MR damper placed diagonally at 0 A current, 3 A current, and without MR damper for a better comparison. The comparative performance indicated the reductions in displacements, increase of forces, and changes in crack patterns. The proposed semiactive damper can, therefore, be used effectively as a seismic resilient device in reducing the structural responses in the regions of moderate to high seismicity.

In recent times, with rapid development in the construction sector, the use of enormous amounts of materials is required for the production of concrete. Fire penetrates concrete, leading to chemical contamination, small cracks, and lightening. These effects can significantly change the properties of concrete’s structure, reduce its strength and durability, and also change the behavior of the structure and lead to effects on the environment. An attempt was made to study the effects of elevated temperature on the mechanical characteristics of self-compacting concrete (SCC) with by-products including fly ash as a partial replacement for cement and waste copper slag as a partial replacement for fine aggregate at 0%, 10%, 20%, 30%, 40%, 50%, 60%, and 70%. The SCC specimens were subjected to elevated temperatures ranging from 200, 400, 600, and 800 °C, respectively, for a steady-state of two hours in a digital muffle furnace. The residual compressive strength, mass loss, ultrasonic pulse velocity, and residual density along with a visual inspection of cracks and color changes were observed. In this study, with over 400 °C temperatures, surface fractures appeared. The residual compressive strength (R-CMS) of all the individual temperatures of the SCC-WCS% mixes exhibited a gain in strength range from 31 to 34 MPa at 400 °C, 26 to 35 MPa at 600 °C, and 22.5 MPa to 33.5 MPa at 800 °C, respectively. Microstructural analysis of SCC-WCS% mixtures subjected to elevated ambient temperatures is carried out with a scanning electron microscope (SEM) and X-ray diffraction (XRD).

In this paper, a vibration control system with magnetorheological (MR) damper investigation is reviewed. At first a MR damper is investigated analytically using various finite element method software and the performance is investigated using experimental. The MR Dampers are designed and modelled for a scaled down setup. The application is in seismic resistance of buildings, automobile, physical and biological. Finally, the damper is investigated using various technique and methods used to study the performance is reviewed. This device reduces the vibration in both active and semi active control system effectively.

Development of a Multiple Coil Magneto-Rheological Smart Damper to Improve the Seismic Resilience of Building Structures