柔性压电纤维复合材料驱动器的驱动特性研究

Actuation characteristics of flexible piezoelectric fiber composite actuator device

本文通过分析柔性压电纤维复合材料驱动器(Flexible Piezoelectric fiber composite actuator Device,FPD)的变形驱动机制,提出了一种基于铁电参数预测其工作电压范围的方法,基于压电方程推导了FPD驱动力的表达式,并经实验测定验证了所提方法的可靠性。此外,基于所提方法研究了有效宽度对机电阻抗性能和驱动性能的影响规律。结果表明:基于铁电参数预测FPD工作电压范围的方法合理可行,FPD的许用工作电压在负向次矫顽电压到正向极化电压之间,且偏置/非对称电压驱动模式可以同步实现大应变和小迟滞;基于压电方程计算FPD驱动力的方法有效可靠,FPD的驱动力正比于其压电应变系数、弹性模量、横截面积及外加电场;随着有效宽度的增加,FPD的电容和驱动能力增加,阻抗减小,主谐振峰、自由应变和迟滞基本不变。

Flexible Piezoelectric fiber composite actuator Device(FPD)is a promising choice for structural actuation and vibration control applications owing to its excellent performance.However,there are few reports about its intrinsic performance parameters that described the actuation behavior,which limits its widespread use and maximum efficiency.Herein,by analyzing the actuation strain mechanism of FPD,a method is proposed to predict its operational voltage range based on ferroelectric parameters and calculate its blocking force based on piezoelectric equation,and the reliability of the method is verified by experimental measurement.Moreover,the influence of the active width on the electromechanical impedance properties and strain actuation performance is investigated.The results show that the prediction for the operational voltage range of FPD from the ferroelectric parameters is reasonable and feasible,and the allowable operational voltage of FPD must be limited between the negative subcoercive voltage and the positive poling voltage.The unsymmetric voltage drive mode can realize large strain and small hysteresis synchronously.The deduction of the blocking force of FPD based on the piezoelectric equation is effective and reliable,and the blocking force of FPD is proportional to its own piezoelectric coefficient,elastic modulus,cross-sectional area and the applied electric field.Furthermore,the capacitance and actuation capability of FPD increase with increasing the active width,while the impedance decreases,the resonant frequency,free strain and hysteresis remain fairly static.