物理学报
物理學報
물이학보
2015年
8期
080503-1-080503-8
,共1页
双稳态系统%能量俘获%相干共振%随机振动
雙穩態繫統%能量俘穫%相榦共振%隨機振動
쌍은태계통%능량부획%상간공진%수궤진동
bistable system%energy harvesting%coherence resonance%random vibration
随着压电晶体材料的迅速发展，基于压电效应的能量采集系统是俘获环境中的宽带随机振动能量的一种有效途径。研究了有限宽带随机激励作用下，磁斥力双稳态压电俘能系统的相干共振俘能机理，并进行了实验验证。运用Euler-Maruyama方法求解了随机非线性压电振动耦合方程，比较分析了相干共振发生前后系统的动力学特性和俘能效率，然后基于Kramers逃逸速率解释了相干共振。最后的随机振动实验结果验证了双稳态压电俘能系统的相干共振俘能机理。并且观察到：当相干共振发生时，系统会在两个势能阱之间剧烈运动，此时宽带随机振动能量会被转化为大幅值窄带低频振动响应，从而极大地提高了宽带随机振动能量的俘获效率。
隨著壓電晶體材料的迅速髮展，基于壓電效應的能量採集繫統是俘穫環境中的寬帶隨機振動能量的一種有效途徑。研究瞭有限寬帶隨機激勵作用下，磁斥力雙穩態壓電俘能繫統的相榦共振俘能機理，併進行瞭實驗驗證。運用Euler-Maruyama方法求解瞭隨機非線性壓電振動耦閤方程，比較分析瞭相榦共振髮生前後繫統的動力學特性和俘能效率，然後基于Kramers逃逸速率解釋瞭相榦共振。最後的隨機振動實驗結果驗證瞭雙穩態壓電俘能繫統的相榦共振俘能機理。併且觀察到：噹相榦共振髮生時，繫統會在兩箇勢能阱之間劇烈運動，此時寬帶隨機振動能量會被轉化為大幅值窄帶低頻振動響應，從而極大地提高瞭寬帶隨機振動能量的俘穫效率。
수착압전정체재료적신속발전，기우압전효응적능량채집계통시부획배경중적관대수궤진동능량적일충유효도경。연구료유한관대수궤격려작용하，자척력쌍은태압전부능계통적상간공진부능궤리，병진행료실험험증。운용Euler-Maruyama방법구해료수궤비선성압전진동우합방정，비교분석료상간공진발생전후계통적동역학특성화부능효솔，연후기우Kramers도일속솔해석료상간공진。최후적수궤진동실험결과험증료쌍은태압전부능계통적상간공진부능궤리。병차관찰도：당상간공진발생시，계통회재량개세능정지간극렬운동，차시관대수궤진동능량회피전화위대폭치착대저빈진동향응，종이겁대지제고료관대수궤진동능량적부획효솔。
Piezoelectric effect is an effective way of harvesting energy from the environmental broadband vibration. In this paper, we investigate the coherence resonance of a piezoelectric bistable vibration energy harvester theoretically and experimentally. The device is comprised of a cantilever beam with magnetic repulsive force. Firstly, the electromechanical coupled equation is derived based on the Euler-Bernoulli beam theory. Then, analyzing the potential shapes, we learn that when the system oscillates between the two potential wells, it will produce a large voltage generally. And the beam dynamic response under the random excitation is simulated by Euler-Maruyama method. The results of simulations and experiments show that there is a coherence resonance threshold in the Du?ng type piezoelectric bistable energy harvester. When the standard deviation of the random excitation is less than the threshold, the motion state of the system will be trapped in a single potential well, which results in a low average output power. And when the excitation standard deviation is larger than the threshold, the system stochastic stability will change. The dynamic displacement and strain clearly show that the system can exhibit large oscillation between the two potential wells. Then, Kramers rate is used to explain the coherence resonance threshold of the bistable system under the broadband random excitation. The experimental results show that when the coherence resonance takes place, the beam will oscillate between the two potential wells more frequently, and the broadband vibration energy can be transformed into large amplitude narrow band low-frequency oscillation response, which can greatly improve the harvesting effectiveness of broadband vibration energy.
