Polyphenylene sulfide-based Langevin transducer

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.