耦合弯曲-剪切载荷L型压电振子的低宽频特性

Low broadband characteristics of L-shaped piezoelectric cantilever beam with bending shear load

针对传统的压电能量采集装置固有频率高、工作频率范围窄及能量转换率低的问题,基于Timoshenko梁理论提出耦合弯曲-剪切载荷的L型压电振子,研究基于L型压电振子的复合压电结构的能量采集特性.根据无线传感器的作业环境特点,研究L型悬臂梁的长度、宽度及延伸段长等因素对压电能量采集频率、输出电压峰值及能量转换效率的影响规律.组合不同尺寸L型压电悬臂梁,研究设计回字形布局的阵列式复合振子.经仿真分析与实验验证结果可知,在0~250 Hz低频环境下,能量采集频率为28~36 Hz、61~68 Hz、92~99 Hz以及103~111 Hz,较等尺寸传统阵列式压电复合振子覆盖频率平均提升了260%.

The L-shaped cantilever beam with coupled bending-shear load was proposed based on the Timoshenko beam theory,and energy capture performance of composite piezoelectric structures of L-shaped piezoelectric cantilever beams was analyzed to solve the problems of high natural frequency,narrow working frequency range and low energy conversion efficiency in traditional piezoelectric energy harvesting devices.The effects of the length,width and length of the L-shaped cantilever beam on the piezoelectric energy acquisition frequency,output voltage peak and energy conversion efficiency were analyzed according to the characteristics of the operating environment of the wireless sensor.L-shaped piezoelectric cantilever beams with different sizes were combined to analyze and design the array-type composite vibrator with a square layout.Simulation calculations and experimental verification results were compared.The energy acquisition frequency was 28-36 Hz,61-68 Hz,92-99 Hz and 103-111 Hz at the environmental low frequency of 0-250 Hz.The frequency was improved by 260%on average compared with the conventional array piezoelectric composite beam of the same size.