Experimental investigation of a novel high performance multi-walled carbon nano-polyvinylpyrrolidone/silicon-based shear thickening fluid damper

Abstract

A novel high performance multi-walled carbon nano-polyvinylpyrrolidone/silicon-based shear thickening fluid (MWCNTs-PVP/SiO2-STF), abbreviated and subsequently referred to as MPS-STF, is developed in this paper. The rheological properties of the MPS-STF are investigated, and the viscosity model of MPS-STF is established. Furthermore, the MPS-STF based viscous fluid damper (MPS-STF-VFD) is designed according to the rheological characteristics of the novel fluid. The impact of loading frequencies, displacement amplitudes and the numbers of piston holes on the dynamic performance of the damper is studied through sophisticated multiple cases loading tests using MTS facility. The test results show that the loading frequency, displacement amplitudes and the number of piston holes have great influence on the rheological properties of MPS-STF. This directly affects the maximum damping force and heat dissipation capacity of MPS-STF-VFD. Finally, the mechanical model of the damper is established based on the principle of fluid mechanics. The simulation results agree well with the experimental data. The high damping performance of the MPS-STF-VFD can be achieved based on the characteristics of the modified fluid. Relevant results reported in this paper can provide an important solution for the development and application of damping technology in engineering structures.

Analysis of Amplification Effect and Optimal Control of the Toggle-Style Negative Stiffness Viscous Damper

“…Meanwhile, it is necessary to ensure the ratio k N /k * T > −0.5, avoiding the TNVD's providing a large negative stiffness, which would significantly reduce the overall stiffness of the structure. (7) The improved TNVD can have good control effects on the inter-layer displacement and story shear force of the structure through the optimization design in Section 3.2. This design method utilizes the optimization strategy of the improved TNVD, which can easily design an improved TNVD damping scheme with larger displacement amplification ability and stronger energy consumption ability.…”

“…Therefore, when the inter-story deformation is U o , the geometric amplification factor γ L of the left TNVD is equal to that of the right TNVD when the inter-story deformation is −U o . U o in Equation ( 6) is replaced by −U o to calculate the horizontal inclination angle θ ′ 1 of the the left TNVD's lower connecting rod, and then it is substituted into Equation (7) to calculate the geometric amplification factor γ L when the inter-story deformation is U o .…”

“…In engineering, the commonly used energy dissipation dampers include viscous dampers, viscoelastic dampers, friction dampers, and metal yield dampers [3][4][5][6]. In addition, other 2 of 26 scholars studied the application of a new-type high-damping fluid damper with shear thickening fluid [7]. This type of energy dissipation damper is usually connected to the structure using supports or intermediate columns, and the upper limit of its deformation or velocity is the inter-layer deformation or velocity of the structure.…”

Synthesis and rheological performance of shear-thickening waterborne polyurethane

“…The abrupt transition from a liquid state to a solid state is due to the formation of aggregates or hydroclusters, which significantly increase the viscosity of the fluid. Due to the unique properties of STFs, they have been used in many areas, including flexible body armor [10], lithium-ion battery safety [11,12], dampers [13,14], and smart wearables [15], etc.…”

“…The artificially synthesized STFs dispersed phase particles generally have regular shapes, uniform particle sizes, good monodispersity, controllable properties, and can easily control their molecular structure and surface charge. Therefore, they are increasingly used in the development of STF [13,22,23].…”