Hybrid control project applied to excessive vibrations in a structure

Abstract

Tuned Mass Dampers tuned (TMD) or Dynamic Absorbers are devices for passive control of vibration in machinery, buildings or other structures. Over the years these devices have improved and become more versatile. In this work, we consider a device with a cubic dependence on displacement in the rigidity of the elastic member coupled to the main mass and connected to the apparatus, both in parallel with a linear viscous damping. The problem is modelled using nonlinear ordinary differential equations to be linearized around its equilibrium point. As a way to excite the TMD, a seismic excitation was used and this is a real spectral function, Tajimi-Kanai spectrum, as in a real situation, the local soil properties produce change in the dynamic properties, thus causing instability in the structure where parameters were used to find a chaotic behaviour in the system. In order to minimize the vibrations caused by seismic excitation was proposed a structural hybrid control. The structural control, basically promotes changes in stiffness and damping of the structure, or by adding external devices, either by the action of external forces. The control technique that is coupled to the TMD is the semiactive control, the magneto rheological damper absorber, in order to minimize vibrations and reduce the chaotic motion of the system to a stable point. The hybrid control strategy adopted demonstrates efficiency for this type of problem and can be used as a way to prevent property loss, damage or buildings ruins.