Semi-active And Passive Vibration Control Of Hybrid Damping Structure

The technology of semi-active shunted circuit in the vibration control is what use piezoelectric component with shunted circuit to buildup a whole damping system. By choosing different shunted circuit form and different electronic component (capacitance, inductance, resistance), a new controllable piezoelectric damping technology is generated by which the vibration of the structure can be restrained.The technology of retraining vibration with semi-active piezoelectric damping has attracted the attention of the scholars over the world. Comparing with the active restraining vibration technology, the semi-active technology does not need very high voltage that is indispensable and hard to active technology. Semi-active technology has not this problem, furthermore, it's structure is simple and easy to realize.In this paper, firstly, some damping structures are compared and their virtue and shortcoming are analyzed. On the basis of these, the semi-active-passive hybrid damping structure is put forward. The mathematics models are build up taking the cantilever beam with capacitance, inductance or resistance shunted circuit for example.Secondly, the inductance is replaced by differential coefficient operation circuit as a suppositional inductance, and the suppositional inductance is adjusted by changing the feedback resistance in differential coefficient operation circuit. Furthermore, the feedback resistance is replaced by photosensitive resistance, and the value of the inductance may be adjusted by changing the voltage LBD gained. Consequently the frequency of the shunted circuit may be adjusted automatically to keep up the frequency of the girder's vibration, and the girder's vibration is restrained mostly.Thirdly, the order of the model established is reduced. The influences on the vibration suppression of viscoelastic layer thickness, viscaoelastic material properties and piezoelectric damping layer thickness are discussed with the indexes defined to featuring the vibration suppression, and some valuable conclusions are obtained.Lastly, experiments of passive constrained layer damping and semi-active piezoelectric damping with shunted circuit are performed respectively, and the restraining effects on vibration are compared.