Harnessing Piezoelectric Shear Actuators for Vibration Control in Sandwich Beams

Abstract

Our study found that integrating shear piezo-transducers inside the beam offers a compact and efficient solution that enables localized damping control without compromising structural integrity. However, the conventional approach of placing the piezos outside the substrate faces challenges and limited accessibility to industrial applications. We determine damping performance for long and slender sandwich beam structures utilizing active vibration control by internally placed piezoelectric shear sensors and actuators. Experimental and numerical results are presented for a clamped-free sandwich beam structure constructed with two stainless steel facings composed of a core layer of foam and a piezoelectric shear-actuator and sensor. This approach of internal actuator and sensor tends to tackle the problems within (high-tech) systems, i.e. mechanical vibrations, a limited amount of design volume, and vulnerability of externally placed piezoelectric transducers to outside conditions. By this new internal sensor-actuator approach, this study addresses a significant gap in the literature. The location of the sensor and actuator has been defined by numerical investigation of the \textit{modal shear strain} and the \textit{effective electro-mechanical coupling coefficient}. The frequency response of the sandwich beam structure has been evaluated using both numerical and experimental investigation. Positive Position Feedback has been employed on the numerical response to simulate the damping performance for the fundamental mode. Different controller gains have been used to analyze the trade-off between effective resonance suppression and increased low-frequency gain. The tip vibrations at the fundamental mode have been reduced from 5.01 mm to 0.34 mm amplitude at steady state, which represents a significant reduction.