建立了悬臂梁结构的半电极含金属芯压电纤维(HMPF)的弯曲振动模型和动态测试模型。基于外加电压时的等效弯矩,推导了悬臂梁结构的HMPF的弯曲振动模型;用第一类压电方程,推导了外加简谐激励电压时,HMPF的表面电位移、电荷和导纳,建立了动态测试模型,通过测量共振频率fr、反共振频率fa和低频电容CLF,得到HMPF的弹性柔顺系数s1E1、机电耦合系数k31、介电常数ε3T3和压电常数d31。叙述了弯曲振动模型和动态测量模型的建立过程和测试步骤,测试了3根HMPF样品,得到各参数的平均值,s1E1为16.856×10^-12 Pa-1,k31为0.179,ε3T3为2 251,d31为-103.621pC/N。测试结果表明所建立的动态测试方法可以快速、准确地测量HMPF的主要参数。
A bending vibration model and a dynamic measuring model for a Half Coated Metal Core Piezoelectric Fiber(HMPF) were established.On the basis of the equivalent bending moment from an applying voltage,the bend vibration model of HMPF for a cantilever structure was deduced.According to the first piezoelectric equation,the surface electric displacements,electric charges and the admittances of the HMPF were derived when the resonant exciting voltage was applied.Then,the dynamic measuring model was established to measure the resonant frequencies,anti-resonant frequencies and the low frequency capacitances and to obtain the main parameters,elastic coefficients sE11,electromechanical coupling factors k31,dielectric constants εT33 and piezoelectric coefficients d31.Three kinds of samples for HMPFs were measured,and their average values are elastic coefficient in 16.856×10-12 Pa-1,electromechanical coupling factor in 0.179,dielectric constant in 2 251 and piezoelectric coefficient in-103.621 pC/N.The theoretical simulation and experimental results show that this method is accurate and available.