基于Morris方法的压电悬臂梁结构参数灵敏度分析

Sensitivity analysis of structure parameters of piezoelectric cantilevered beam based on Morris method

作为常见俘能器之一的压电俘能器,其结构参数的合理化设计决定着俘能器输出功率的大小,分析影响压电俘能器输出功率的关键结构参数具有十分重要的意义。以压电双晶梁为研究对象,运用Morris方法对其结构参数进行了全局灵敏度分析,并使用正交试验方法对灵敏度排序结果进行验证。结果表明,在给定参数变化范围内,压电梁厚度和长度分别是影响谐振频率和峰值功率的两个最重要参数。压电梁宽度对系统输出性能影响最小,且与其它参数的交互性相对较弱。灵敏度分析方法对压电悬臂梁结构优化设计具有指导意义。

The piezoelectric energy harvester(PEH)is a kind of conventional vibration energy harvester.Higher power output of the PEH can be achieved by a rational design of the structural parameters,which means that it is extremely significant to study the effect of the structural parameters on the power outputs of the PEH.Based on the global sensitivity analysis procedure from the Morris method,in this paper,the sensitivities of a double crystal piezoelectric cantilevered beam are computed,where the main structural parameters of the piezoelectric beam are selected as the design parameters.The values of the objective function introducing the design parameters are obtained by the finite element analysis method.An orthogonal test method is used to verify the sensitivity ranking from Morris method.The results show that both the thickness and the length of the piezoelectric beam are the most significant two parameters affecting the resonance frequency and the peak power outputs of the harvester.The width of the beam has a weaker effect on the output performance of the system and its interactivity with other structural parameters is also relatively weaker.The study based on the sensitivity analysis method is significant in guiding structural optimization design of a piezoelectric cantilevered beam.