Active vibration suppression of sandwich beams using piezoelectric shear actuators: Experiments and numerical simulations

This article deals with the experimental and numerical assessment of the vibration suppression of smart structures using piezoelectric shear actuators. Experimental results are presented for an adaptive sandwich cantilever beam that consists of aluminum facings and a core composed of two piezoelectric shear actuators and foam. The electric field is applied perpendicular to the poling direction of the piezoelectric actuators to cause transverse shear deformation of the sandwich beam. Active vibration suppression is achieved using either positive position feedback or strain rate feedback. The control system is implemented in real-time using Matlab/Simulink and a dSPACE digital controller. First, the frequency response of the adaptive beam is investigated by using one shear actuator to excite the beam and the other to control its vibration. Parametric studies are conducted to assess the influence of controller parameters on the frequency response of the system. The experimental frequency response function compares well with numerical simulations using the finite element method. Next, the effectiveness of the active vibration suppression system in the time domain is analyzed using a proof-mass actuator that is attached to the tip of the cantilever beam to provide a repeatable vibration input. Experiments and numerical simulations show that the shear actuators can provide significant reduction in tip acceleration and settling time.