The quality of collected electric power is directly affected by the mechanical properties of piezoelectric cantilever, which is an important part of vibration energy collection system. A piezoelectric energy harvester is employed to study the electromechanical conversion performance of piezoelectric cantilever under different counterweights by adding mass blocks. An experimental platform is built to test the piezoelectric energy harvester based on numerical analysis. The effects of different mass attached to the cantilever on frequency bandwidth and phase angle difference are studied. The numerical analysis indicates that the output voltage of the two piezoelectric bimorphs in series is higher than that of the single piezoelectric plate, and the natural frequency of the structure changes little. The mass is the main factor affecting the resonant frequency and output voltage of the energy harvester based on the expression of natural frequency. The experimental results show that the maximum output voltage increases by 39.42% and the natural frequency decreases by 13.83% when the mass ratio is 11.75%, which is consistent with the numerical results. The increasing of counterweight causes the decrease of third-order natural frequency of piezoelectric cantilever and the increase of frequency bandwidth. It is demonstrated that the phase difference decreases rapidly and finally approaches to − 180° when the external excitation frequency is near the resonant frequency. The phase difference at the peak is close to zero when the mass ratio is 11.75%, corresponding to the highest voltage output. The results have reference significance for the system adaptive tuning of vibration energy harvester.

压电悬臂的机械性能直接影响收集到的电能质量，压电悬臂是振动能量收集系统的重要组成部分。通过添加质量块，利用压电能量采集器来研究不同配重下压电悬臂梁的机电转换性能。建立了一个基于数值分析测试压电能量采集器的实验平台。研究了悬臂上附着的不同质量对频率带宽和相位角差的影响。数值分析表明，串联的两个压电双压电晶片的输出电压均高于单个压电板的输出电压，结构的固有频率变化很小。质量是基于固有频率的表达影响能量收集器的谐振频率和输出电压的主要因素。实验结果表明，当质量比为11.75％时，最大输出电压增加39.42％，固有频率降低13.83％，与数值结果一致。配重的增加导致压电悬臂梁的三阶固有频率的下降和带宽的增加。结果表明，当外部激励频率接近谐振频率时，相位差迅速减小，最终达到-180°。当质量比为11.75％时，峰值处的相位差接近于零，对应于最高电压输出。