Effect of local strain on active vibration control of smart structures using symmetricly bonded piezoelectric patches

For vibration control, piezoelectric actuators and sensors are always bonded symmetricly on opposite sides of thin plates or beams. In the experiment, it is found the piezoelectric sensors are affected by the local strains of patches so that the control performance decreases. In order to further study the local strain effect, the harmonic response of a thin plate was analyzed by using ANSYS. The amplitudes and phases of the output voltages of sensing patches installed at symmetrical positions were compared to theoretically verify the local strain existence. Square wave excitation experiments and vibration control experiments making use of MCS(Minimal Controller Synthesis) algorithm on an aircraft panel demonstrate the influence of local strains. The results provide a good foundation for further improving the active control effect.