Monitoring of viscous damper fluid viscosity using piezoceramic transducers—a feasibility study

Abstract

The viscosity of the fluids inside a viscous damper is essential for the energy absorption and dissipation capabilities of the damper. However, service-induced changes in viscosity can significantly reduce the seismic performance of viscous dampers over time. Hence, it is necessary to develop an effective approach to monitor the viscosity of fluids in dampers. In this paper, an active sensing method to monitor the viscosity of fluids with piezoceramic transducers is proposed. Two transducers are installed inside a damper to separately function as an actuator and a sensor to respectively emit and receive vibration signals. The relationship between the viscosity of the fluids and the signal amplitude is analyzed from the perspective of the one-dimensional wave theory. A viscosity variation index (VVI) is defined to quantify the relationship between the amplitude of received signals and the fluid viscosity. Numerical results show that the VVI decreases exponentially with the increasing viscosity of the damper's fluids. The experimental results agree well with the numerical analysis, thus validating the feasibility of the proposed approach.

Shear horizontal wave dispersion in two phase magneto-electro-elastic material loaded with viscoelastic fluid layer

“…the real part k r ( ) describe the phase velocity of the SH wave and the imaginary part (k i ) describe the wave attenuation induced by the viscoelastic fluid layer. After substitution of equation (22) into equations (3) and ( 15)-( 17), the y-dependent function can be written as…”

“…As a result, when designing suitable devices, the attenuation of the SAW and the leakage of wave energy into the liquid should be taken into account. Researchers have extensively delved into the intricacies of SAW propagation in diverse structures, encompassing elasticity, piezoelectricity, piezomagnetism, and electromagnetism within layered configurations loaded with viscous liquids [19][20][21][22][23]. The BG wave stands out as a promising candidate for liquid sensing due to its unique ability to propagate on the surface of a piezoelectric substrate without the need for an additional guiding layer.…”

Monitoring of Liquid Viscosity for Viscous Dampers through a Wireless Impedance Measurement System

“…Chen at al. used the wave propagation method to monitor the viscosity of fluids [45]. While the above methods have unique benefits for the precise and accurate monitoring of damage, all require wired connections, which can impede practical implementation.…”