Research and Development of Smart Viscous Damper(I)

Research and Development of Smart Viscous Damper(I)

A significant number of researchers are convinced that the structural response could be reduced appropriately by installing damper devices. However, the damper deployed on buildings or bridges are generally designed only for the specific structural system under specific loading conditions. As a result, several researchers have developed the adjustable passive damper in recent years. Electro rheological dampers(ER dampers) and magneto rheological dampers(MR dampers) are well known adjustable damper systems, but the durability and the stability of the external power supply needed for ER and MR dampers are questionable for the long-term application during structure service life. Consequently, a new material, shear thickening fluids(STF), which changes its properties according to different loading rate without external power needed, is considered to be a good filled material for innovative damper devices. In this paper it will be shown that applying STF materials on a conventional viscous damper device by using a simplified piston device and changing the concentration of STF filled can develop an innovative viscous damper which behaves like the MR damper. In this study, STF samples composed of three different sizes of silica nanoparticles(12, 16 and 40 nm) suspended in three types of solvent(polypropylene glycol, PPG) were fabricated in the laboratory. The shear properties of STF samples under the steady state and the oscillatory state were tested separately by using a rheometer. Furthermore, a prototype STF damper was developed and tested with preliminary performance experiments. Besides, hysteretic loops of the STF damper developed under various loading conditions were observed. The result shows the smart STF damper proposed in this paper might have a good potential in practical engineering applications.