聚苯硫醚材料复合棒型换能器

Polyphenylene sulfide-based Langevin transducer

本文选择了高聚物中杨氏模量较大、损耗较小的聚苯硫醚作为复合棒型换能器的前盖板.计算了聚苯硫醚棒中的纵波传播速度,研究了基于聚苯硫醚材料的复合棒型换能器的等效电路设计方法。利用有限元方法计算了换能器谐振频率、轴向应变分布、平均耗散功率等性能参数。对本文研制的前盖板为聚苯硫醚、后盖板为钢(1#)和前后盖板均为聚苯硫醚(2#)的两个换能器进行了测试.结果表明,理论计算的谐振频率与实验测试相吻合;两个换能器的振幅均与所施加的电压成正比,且1#换能器的振幅电压比更大;两个换能器的耗散功率与加电压平方成正比,在应变较大处耗散功率较高,导致局部升温明显,测得两个换能器温度最高处均位于应变最大位置处。1#换能器的前后振幅比为26,与同频率的金属组件换能器相比,若后盖板为尺寸相同的钢材,前盖板采用聚苯硫醚材料能够显著提高换能器的前后振幅比,且带宽也较大。

The polymer material polyphenylene sulfide with high Young's modulus and low loss is selected as front head of the Langevin transducer in this work.The longitudinal wave velocity in polyphenylene sulfide rod is calculated.The design method of electromechanical equivalent circuit of the polyphenylene sulfide-based Langevin transducer is studied,and the parameters such as the resonance frequency,distribution of the longitudinal strain,average dissipated power of the transducer are calculated by using finite element method.The two transducers are fabricated,whose front head is made by polyphenylene sulfide and rear end made by steel(1#);both the front head and rear end are made by polyphenylene sulfide(2#),and then tested.The results show that the resonance frequency obtained by the theoretical calculation is consistent with the experimental test;the vibration amplitudes of both the transducers are proportional to the voltage applied to the transducer,and the ratio of the vibration amplitude to voltage of 1#transducer is greater.The dissipated power is proportional to the square of the applied voltage of both the transducers,and higher dissipated power of both the transducers is located at where the strain is larger,which leads to significant local heating.Test also verifies that the highest temperature of both the transducers is in the same place as the highest strain.The ratio of the vibration amplitude of the front head to rear end of 1#transducer is 26.Compared with conventional metal transducer with the same resonance frequency,which rear end is made of steel of the same size,when the front cover is made of polyphenylene sulfide,the ratio of the vibration amplitude of front head to rear end of the transducer can be significantly improved,and the frequency band is wider.