基于电压的压电悬臂梁剩余寿命预测

Residual life prediction of piezoelectric cantilever beam based on voltage

压电悬臂梁广泛应用于振动能量收集器的设计。然而,长期经受振动激励很容易导致其产生疲劳损伤,致使压电体发生失效。旨在研究一种基于电压的压电悬臂梁剩余寿命预测方法,实现压电悬臂梁的寿命预测。首先,设计压电悬臂梁振动试验系统,测试压电悬臂梁的共振频率、发电电压和循环加载次数。然后,基于试验测得的共振频率定义损伤,建立电压变化与损伤的关系。最后,以电压变化率为损伤指针,建立压电悬臂梁的剩余寿命预测模型,利用试验结果证实寿命预测模型的准确性。结果表明,共振频带激励下,该模型可预测压电悬臂梁的剩余寿命,损伤率D在0.4~0.8区间内,预测误差小于15%;当损伤率D在0.8~1.0区间内,误差小于5%;当D小于0.4时,误差较大。

Piezoelectric cantilever beam is widely used in design of vibration energy harvester.However,long-term bearing vibration load can easily make the beam have fatigue damage and its piezoelectric body be failure.Here,a residual life prediction method for piezoelectric cantilever beam based on voltage change was proposed to realize its life prediction.Firstly,a vibration test system was designed to measure piezoelectric cantilever beam’s resonance frequency,generating voltage and numbers of cyclic loading.Then,the measured resonance frequency was used to define damage,and the relation between voltage change and damage was established.Finally,the voltage change rate was taken as the damage indicator to establish the residual life prediction model of piezoelectric cantilever beam,and the correctness of the established model was verified with test results.It was shown that under the excitation within resonance frequency band,the model can predict the residual life of piezoelectric cantilever beam,the damage rate D is in the range of 0.4-0.8,the prediction error is smaller than 15%;when the damage rate D is in the range of 0.8-1.0,the error is smaller than 5%;when D is less than 0.4,the error is larger.