Experimental and numerical investigation of a fluid inerter for structural control

In the study presented here, the dynamic properties of a fluid inerter, including nonlinear effects, are characterized and the degree of its effectiveness in structural control is assessed. A fluid inerter is a mechanical device that models an element with unit of mass whose mass property (called inertance) greatly exceeds its physical mass. To this end, a small-scale prototype is realized and experimentally investigated. Linear and nonlinear parameters are identified to obtain a mechanical model suitable for more accurate parametric studies. Numerical simulations based on a finite element model are performed to evaluate the effects of the air unavoidably trapped in the system. In order to apply the device to engineering problems in more general configurations, a linearization procedure is performed for the nonlinear system elements and a comparison is made between the real and the linearized system.