Optimal damping compensation of a dynamic vibration absorber using an electromagnetic resistive shunt.

This study focuses on the addition of an electromagnetic (EM) resistive shunt (R-shunt) to a standard mechanical Dynamic Vibration Absorber (DVA) to replace, compensate or tune its damping element. The R-shunt is placed between the mass of the DVA and the host structure. The inclusion of the R-shunt introduces an additional pole in the frequency response function of the host structure, resulting in three fixed points. Analysing these fixed points enables the optimisation of the absorber with the objective of minimising the H$_\infty$-norm of both displacement and acceleration of the structure. In both cases, a thorough optimisation of the obtained DVA+R-shunt absorber, in terms of mass ratio, electromagnetic coupling factor (EMCF) and electric resistance, is proposed. The response of this absorber is then compared to that of an optimised standard DVA, leading to equivalent performance when the parameters are correctly chosen. For optimal performance, the DVA must be detuned with respect to standard optimisation and the EMCF of the R-shunt must be adjusted to an optimal value, contrary to standard shunts where the performance often increase as a function of the EMCF. Finally, an experimental study validates the effectiveness of the proposed device.