电压特性对压电纤维复合物驱动性能的影响

Effect of voltage characteristic to driving property of piezoelectric fiber composites

压电纤维复合物因机电响应速度快、驱动能力强和柔性佳成为智能材料领域的研究热点之一。压电纤维复合物作为驱动器时,在不同的应用领域对于驱动电压特性有不同的要求。本文通过自由应变和悬臂梁顶端位移研究压电纤维复合物在不同电压幅值、偏置、波形下的驱动应变性能。结果表明:随着驱动电压幅值增大,压电纤维复合物自由应变值和驱动性能随之增大。压电纤维复合物的横向和纵向自由应变分别随着电压偏置的增大而降低,相应的悬臂梁顶端位移量减小。当用方波驱动时压电纤维复合物的纵向自由应变值和横向自由应变值分别为2061.4×10^(-6)和574.9×10^(-6),顶端位移量为1.614mm,比正弦波和锯齿波的驱动值更大,其原因主要是电压的阶跃性导致瞬间施加在压电纤维上的电场强度较大。

As one of the smart materials, the piezoelectric fiber composites(PFCs) have shown superior performance in aspects of flexibility, high electromechanical response rate and long service life. The requirements of the driving voltage properties were different when the PFCs were used in various areas. In this paper, the strain of PFCs and the tip displacement of the cantilever beam were studied under different driving conditions, including the amplitude, bias and waveform of voltage. The results show that the actuating properties of PFCs, such as strain and the tip displacement of cantilever beam increase when the amplitude of driving voltage amplifies. Both the transverse and longitudinal strain of the PFCs decrease when the bias of voltage amplifies. After being driven by square-wave alternating voltage, the transverse and longitudinal strain of PFCs are 2061.4×10-6 and 574.9×10-6, respectively, which are larger than those driven by sine-wave and sawtooth-wave voltage. It is mainly due to the step characteristic of voltage.