Self-powered synchronized switch damping on negative capacitance for broadband vibration suppression of flexible structures

Synchronized switch damping (SSD)techniques using piezoelectric materials have been used by different researchers for many years for the structure vibration control. In these techniques, a piezoelectric patch is bonded on or embedded into the vibrating structure and connected to or disconnected from a network of electrical components through an electronic switch, which is controlled by a digital signal processor (DSP), in synchronous with the structure motion. Recently, Self-powered SSD techniques have emerged in which the DSP is replaced by a low pass filter, thus making the whole system self-powered. The control performance of the previously used Self-powered SSD techniques heavily relied on the electrical quality factor of the shunt circuit, thus limiting their control performance as the electrical quality factor could not be increased beyond certain limit. However, in order to bypass the influence of the electrical quality factor on the control performance, a new Self-powered SSD technique has been proposed in this paper in which the inductance in the previous Self-powered SSD techniques has been replaced with a negative capacitance thus making the whole circuit capacitive without resonance. However, it is found that the voltage on the piezoelectric patch can still be inverted. In order to access the control performance of the proposed technique in comparison with the previous Self-powered SSD techniques, experiments are performed on a cantilever beam subjected to both single mode and multimode excitations. Keeping the value of negative capacitance slightly greater than the inherent capacitance of the piezoelectric patch gave the optimum damping performance. Experiments results confirmed the effectiveness of the proposed technique as compared to the previous SSD techniques.