CAJ | 학술논문

压电叠层作动器在结构振动控制及其它场合表现出良好应用前景，建立能够反映其物理本质的数学模型非常重要。以压电材料的本构关系以及杆的纵向振动方程为基础，考虑外部阻抗的影响，推导了短路机械阻抗、电阻抗以及转换系数的表达式，并构造了转换方程，从而建立了能够描述压电叠层作动器与主体结构之间机电耦合特性的阻抗模型。理论分析和数值模拟结果表明外部阻抗对这些参数有重要影响：当两端的外部阻抗完全相同时，作动器的电阻抗和转换系数有最高的共振频率，作动器可看成两个具有固定-自由边界条件的作动器的串联。其它情况下则均有不同程度的降低。因此，为实现更好的控制效果需要考虑阻抗匹配问题。
압전첩층작동기재결구진동공제급기타장합표현출량호응용전경，건립능구반영기물리본질적수학모형비상중요。이압전재료적본구관계이급간적종향진동방정위기출，고필외부조항적영향，추도료단로궤계조항、전조항이급전환계수적표체식，병구조료전환방정，종이건립료능구묘술압전첩층작동기여주체결구지간궤전우합특성적조항모형。이론분석화수치모의결과표명외부조항대저사삼수유중요영향：당량단적외부조항완전상동시，작동기적전조항화전환계수유최고적공진빈솔，작동기가간성량개구유고정-자유변계조건적작동기적천련。기타정황하칙균유불동정도적강저。인차，위실현경호적공제효과수요고필조항필배문제。
Piezoelectric stack actuators have great potential in structural vibration control and other applications, and it is critical to build a mathematic model to depict their important physical behaviors.An impedance-based model to describe their electromechanically coupled characteristics was developed here.Short circuit mechanical impedance matrix, electric impedance and conversion coefficients were derived based on a rod's longitudinal vibration equation and constitutive relationships of piezoelectric materials.Conversion equations in a matrix form representing the electric-mechanical interaction between the actuators and the main-body structure were built.Numerical simulations are also conducted to verify the theoretical derivation.Both theoretical analysis and simulation results showed that the impedances of external structures attached to the actuators have a significant influence on the three types of parameters mentioned above;the resonance frequency for the electric impedance of the actuator and conversion coefficients is the highest when the external impedances of two ends are exactly equal, and decreases for other cases;the influences of external impedances need to be considered to get a satisfactory control.