Design of damper viscous properties for semi-active control of asymmetric structures

A method to design semi-active control strategies of asymmetric structures is presented. The method is based on the optimal sizing of an equivalent Kelvin-Voight model describing the constitutive behavior of semi-active magneto-rheological devices, through the evaluation of the maximum achievable modal damping when they work in passive modality. The complex eigenvalue loci of the passively-controlled system versus the device mechanical characteristics are spanned for symmetric and asymmetric frame structures. A coherent representation of the reference effect ensured by an optimized linear active feedback on the eigenvalues loci is selected to drive the design of the adjustable properties of the semi-active device. A clipped-optimal control algorithm is used in a prototype experimental application whose performance are highlighted by the presented design method.