基于压电振动系统的Lagrangian方程,推导了含附加谐振器的压电俘能器机电耦合动力学模型,给出了输出电压的频域表达式,探讨了谐振器中弹簧刚度、质量块质量、阻尼系数以及负载电阻、激振频率等参数对输出电压的幅频特性的影响。分析结果表明:附加谐振结构使得压电俘能器出现二阶谐振,随着弹簧刚度的增加,二阶谐振频率逐渐增加;随着质量块质量的增加,二阶谐振频率逐渐减小;阻尼系数仅对二阶谐振峰值有影响,且峰值随阻尼系数的增加而减小;一阶谐振峰值随激振频率的增加而增加,且一阶谐振频率逐渐向二阶谐振频率偏移;负载电阻不影响谐振频率,系统输出电压和输出功率随着负载电阻的增加而增加。
Based on the Lagrangian equation of piezoelectric system ,this paper proposes an electrome-chanical coupling model of the piezoelectric energy harvester ,presents the expression for output vol-tage of the frequency domain and discusses the effect of the spring stiffness ,mass ,damping coeffi-cient ,excited frequency and load resistance on the amplitude-frequency characteristics of output vol-tage .The results show that the second resonant frequency which is caused to appear in the piezoelec-tric energy harvester by the dynamic absorber increases gradually with the spring stiffness ,and de-creases gradually as the mass result increases ;the damping coefficient only affects the peak value of second resonant frequency ;the first resonant frequency peak value increases with the excited frequen-cy ;the output voltage and power increase with load resistance ,which has no influence on resonant f requency .