Chen Cheng, Wang Sha, Tian Hua, Lin Shuyu
Shaanxi Key Laboratory of Ultrasonics, Institute of Applied Acoustics, Shaanxi Normal University, Xi'an 710119, China.
Ultrasonics. 2021 Dec;117:106546. doi: 10.1016/j.ultras.2021.106546. Epub 2021 Aug 2.
In order to improve the acoustic radiation capability of piezoelectric ultrasonic transducer in gas, a bimorph rectangular transducer based on type 2-2 piezoelectric composites is proposed in this paper, which is composed of two piezoelectric composite rectangular slices with thickness polarization. First, the bending vibration of the rectangular transducer is divided into two bending vibrations of the thin rods in the x and y directions using the equivalent elastic method. When the mechanical coupling coefficient is introduced and combined with the anisotropic piezoelectric equations, the resonance frequency equations of the thickness-polarized transducer are derived with simply supported boundary conditions. Then the bending vibration of the transducer is numerically simulated. The results show that the resonance frequency obtained by the analytical method is in good agreement with the numerical simulation results. Finally, the influence of geometrical size and two-phase volume ratio on the bending vibration performance of the transducer is analyzed. Compared with the piezoelectric bimorph transducer, the piezoelectric composite bimorph transducer has a larger bending vibration displacement amplitude, a larger transmitting voltage response, a lower resonant frequency and better acoustic radiation capability.
为了提高压电超声换能器在气体中的声辐射能力，本文提出了一种基于2-2型压电复合材料的双压电晶片矩形换能器，它由两个具有厚度极化的压电复合矩形片组成。首先，利用等效弹性方法将矩形换能器的弯曲振动分解为x和y方向细杆的两个弯曲振动。引入机械耦合系数并结合各向异性压电方程，推导了简支边界条件下厚度极化换能器的共振频率方程。然后对换能器的弯曲振动进行了数值模拟。结果表明，解析方法得到的共振频率与数值模拟结果吻合良好。最后，分析了几何尺寸和两相体积比对换能器弯曲振动性能的影响。与压电双压电晶片换能器相比，压电复合双压电晶片换能器具有更大的弯曲振动位移幅值、更大的发射电压响应、更低的共振频率和更好的声辐射能力。
