基于PZFlex的1-3压电复合材料横向振动模仿真

1-3型压电复合材料具有高机电耦合系数和低声阻抗,适用于制作水声和医疗超声换能器,但是1-3型压电复合材料的横向振动模会降低换能器的性能,限制换能器的小型化和高频化。该文设计了一组具有矩形压电陶瓷柱的1-3型压电复合材料,复合材料的厚度为0.32 mm,陶瓷柱宽度为0.08 mm,长度为0.10~0.25 mm,刀缝宽度为0.05 mm。利用有限元软件PZFlex进行了建模计算,仿真结果表明,复合材料的厚度谐振频率和反谐振频率分别为4.5 MHz、6 MHz,随着陶瓷柱长度的增大,横向谐振频率逐渐向低频处移动,当陶瓷柱长度和高度比值大于0.69时,横向谐振和厚度谐振发生模式耦合。该文基于复合材料设计了换能器,利用PiezoCAD软件计算得到换能器的中心频率为4.7 MHz。

Simulation of Lateral Resonance Mode of 1-3 Piezo-composite Based on PZFlex

The 1-3 piezo-composites with high electromechanical coupling coefficient and low acoustic impedance are suitable for fabricating hydrophone and medical ultrasound transducers. However, the lateral mode resonances of 1-3 piezo-composites will reduce the performance of transducers and limit the miniaturization and high frequency of transducers. In this work, a set of 1-3 piezo-composites with rectangular ceramic pillars are designed. The thickness of piezo-composites is 0.32 mm. The width of ceramic pillars is 0.08 mm and the length of ceramic pillars varies from 0.10 mm to 0.25 mm, the kerf is 0.05 mm. The modeling and calculating has been carried out by using the PZFlex finite element software. The simulation results show that the thickness mode resonant frequency and anti-resonant frequency of the composites are 4.5 MHz and 6 MHz, respectively. The lateral mode resonant frequency gradually shifts to the low frequency with the increase of the length of the ceramic pillars. The thickness mode and lateral mode are coupled when the ratio of length to height of ceramic pillar is greater than 0.69. The transducer is designed based on the composite and the center frequency of transducer is 4.7 MHz according to the PiezoCAD software.