旋转轮胎中压电悬臂梁离心距优化

针对压电悬臂梁在低频区域内响应较差的问题,该文基于自调节随机共振提出了一种在旋转轮胎中优化悬臂梁末端磁铁离心距的方法。首先分析推导出了末端磁铁的动力学方程,然后以Kramers逃逸速率为基础,建立了自调节随机共振频率与旋转频率的优化函数,得到最优离心距匹配机理,最后运用最优离心距匹配机理得到最优离心距,并比较了不同离心距下压电悬臂梁的位移、速度和电压响应。结果表明,当离心距达到优化值时,在某一频率范围内,随机共振频率随着旋转频率可持续产生共振现象,其有效响应频带扩展至30~50 rad/s,拓宽频带比约40%,有效提升了能量俘获性能。

Research on Optimization of Centrifugal Distance of Piezoelectric Cantilever Beam in Rotating Tire

Aiming at the problem of poor response of piezoelectric cantilever in low frequency region, a method to optimize the centrifugal distance of the magnet at the end of the cantilever is proposed based on self-tuning stochastic resonance. Firstly, the dynamic equation of end magnet is analyzed and deduced. Then the optimization function of self-tuning stochastic resonance frequency and rotation frequency is established based on the Kramers escape rate, and the optimal centrifugal distance matching mechanism is obtained. Finally, the optimal centrifugal distance is obtained by using the optimal centrifugal distance matching mechanism, and the displacement, velocity and voltage responses of the piezoelectric cantilever under different centrifugal distances are compared. The results show that when the centrifugal distance reaches the optimal value, in a certain frequency range, the stochastic resonance frequency follows the rotation frequency, the stochastic resonance phenomenon can occur continuously, and its effective response frequency band is extended to 30~50 rad/s, and the ratio of broadening the frequency band is about 40%, and the energy harvesting performance is effectively improved.