【摘要】 提出一种变截面悬臂梁压电俘能器结构,通过有限元仿真分析其振动特性和输出电压,有利于提高发电性能。该俘能器结构固定端为等截面梁,自由端为变截面梁,压电层粘贴在悬臂梁根部等截面梁表面,改变悬臂梁自由端与固定端的宽度比,得到多种不同形式的变截面悬臂梁。对比分析了三角形梁、矩形梁和具有不同宽度比梯形梁的固有频率、应力和应变分布及简谐激励输出电压响应。结果表明,三角形梁固有频率较大,输出电压最大,同时分析了不同变截面段长度对输出电压的影响。该文还分析了具有相同一阶频率、不同宽度比俘能器的输出电压,表明三角形结构单位体积压电层输出电压最大。对比分析了基体层上根部粘贴压电片和全部粘贴压电片的输出电压特性。结果表明,前者输出电压较大,发电性能更好。更多还原

【Abstract】 A variable cross-section cantilever beam structure for the piezoelectric energy harvester is proposed in this paper.The finite element simulation analysis of the vibration characteristics and output voltage shows that the proposed structure is beneficial to improve the power generation performance.The fixed end of the energy harvester is a uniform cross-section beam and the free-end is a variable cross-section beam.The piezoelectric layer is adhered on the surface of the uniform cross-section beam.A variety of different forms of variable cross-section cantilever beam can be obtained by changing the width ratio of the free-end to the fixed end of the cantilever beam.The natural frequencies,stress and strain distributions as well as the output voltage response of harmonic excitation of the triangular beam,rectangular beam and the trapezoidal beam with different widths ratio are compared and analyzed.The results show the triangular beam exists higher natural frequency and maximum output voltage.The effects of different variable cross-section range lengths on the output voltage are analyzed.The output voltage of different width ratio energy harvester with the same first order frequency is analyzed,which shows that the output voltage of the unit volume piezoelectric layer of triangle structure is the largest.The output voltage characteristics of the root-bonded piezoelectric patches and the all-bonded piezoelectric patches on the base layer were compared and analyzed.The results show that the former has a larger output voltage and better power generation performance.更多还原