基于力电响应的压电悬臂梁疲劳寿命预测

Fatigue life prediction of piezoelectric cantilever beam based on electromechanical response

针对压电振动能量收集器的疲劳问题,旨在研究基于力电响应的压电悬臂梁振动疲劳寿命预测方法。结合压电悬臂梁振动疲劳试验测得的试验结果,以剩余刚度理论和“两段式”疲劳寿命分析模型为基础提出一种基于谐振频率的压电悬臂梁疲劳寿命预测方法;进一步分析振动疲劳过程中谐振频率变化与负载功率变化的关系模型,提出一种基于负载功率的压电悬臂梁疲劳寿命预测方法。结果表明:基于谐振频率的压电悬臂梁疲劳寿命预测方法的平均误差在10%~20%之间,其误差范围控制在1.5倍误差线以内;而基于负载功率的压电悬臂梁疲劳寿命预测方法的平均误差集中于25%左右,误差范围均控制在2倍误差线以内且属于偏安全的预测效果。

Here,aiming at the fatigue problem of piezoelectric vibration energy collectors,the method to predict vibration fatigue life of piezoelectric cantilever beam based on electro-mechanical response was studied.Based on test results obtained with vibration fatigue tests of piezoelectric cantilever beam,a fatigue life prediction method for piezoelectric cantilever beam based on resonance frequency was proposed based on the residual stiffness theory and the“two-stage”fatigue life analysis model.Furthermore,the relation model between resonance frequency changes and load power changes in vibration fatigue process was analyzed,and a fatigue life prediction method for piezoelectric cantilever beam based on load power was proposed.The results showed that the average error of the fatigue life prediction method for piezoelectric cantilever beam based on resonance frequency is between 10%~20%,and the error range is controlled within 1.5 times the error line;the average error of the fatigue life prediction method for piezoelectric cantilever beam based on load power is concentrated around 25%,and the error range is controlled within 2 times the error line,so this method has a relatively safe prediction effect.