双晶压电悬臂梁俘能器的建模与仿真

Modeling and simulation of bimorph cantilever piezoelectric energy harvester

针对双晶片悬臂梁式压电俘能器的优化问题,考虑悬臂梁末端位移与质量块质心位移的差异,对Roundy数学模型进行了修正。通过ANSYS有限元软件对俘能器建模并进行模态分析和谐响应分析,当质量块长度逐渐变大时,修正后数学模型对俘能器一阶固有频率和输出电压有更好的预测精度。研究了质量块形状和负载对俘能器输出特性的影响规律,发现在质量块质量不变时,提高质量块的质心高度能提高俘能器的发电能力,对俘能器的结构优化具有借鉴意义。

To solve the optimization problem of bimorph cantilever piezoelectric energy harvester,the Roundy mathematical model is modified,where difference between the deflection at the center of the proof mass and that at the end of the cantilever is considered. By using the finite element software of ANSYS,modal analysis and harmonic response analysis of energy harvester model are carried out. The results show that modified model is more accurate than Roundy model in predicting the first order natural frequency and output voltage of the harvester when the length of mass block grows. Influence law of mass block shape and load on energy harvester output characteristics is studied,it is found that when the weight of mass block is constant,mass block with a higher center of mass will make the energy harvester have a better generating capacity,and the result has reference significance for structural optimization of the piezoelectric energy harvester.