Piezoelectric Shunt Stiffness in Rhombic Piezoelectric Stack Transducer with Hybrid Negative-Impedance Shunts: Theoretical Modeling and Stability Analysis

Abstract

Negative-capacitance shunted piezoelectric polymer was investigated in depth due to its considerable damping effect. This paper discusses the novel controlled stiffness performance from a rhombic piezoelectric stack transducer with three hybrid negative-impedance shunts, namely, negative capacitance in series with resistance, negative capacitance in parallel with resistance, and negative inductance/negative capacitance (NINC) in series with resistance. An analytical framework for establishing the model of the coupled system is presented. Piezoelectric shunt stiffness (PSS) and piezoelectric shunt damping (PSD) are proposed to analyze the stiffness and damping performances of the hybrid shunts. Theoretical analysis proves that the PSS can produce both positive and negative stiffness by changing the negative capacitance and adjustable resistance. The Routh–Hurwitz criterion and the root locus method are utilized to judge the stability of the three hybrid shunts. The results point out that the negative capacitance should be selected carefully to sustain the stability and to achieve the negative stiffness effect of the transducer. Furthermore, negative capacitance in parallel with resistance has a considerably better stiffness bandwidth and damping performance than the other two shunts. This study demonstrates a novel electrically controlled stiffness method for vibration control engineering.

Piezoelectricity performance and β-phase analysis of PVDF composite fibers with BaTiO3 and PZT reinforcement

“…The intensity of the peaks established at low weight percentages used is the minimum due to the small amounts of BaTiO 3 and PZT added to the composite fibers, and the intensity of the revealed peaks increases with the increase in weight percentage. As a consequence, the investigation revealed that the characteristic peak of BaTiO 3 occurred at 2θ = 32.17° (110) [ 41 ], and the increase in the intensity of the PZT peaks at 2θ = 32° (110) and 22° (101) showed an increased amount of PZT in the fiber structure [ 42 ].…”