ULTRASONIC INPUT OUTPUT CHARACTERISTICS FOR TRANSMITTING AND RECEIVING CONTACT TYPE TRANSDUCERS COUPLED TO A TIMOSHENKO BEAM

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Acousto ultrasonic input output characteristics for transmitting and receiving contact type transducers coupled to a Timoshenko beam waveguide are considered. By means of a multiple integral transform method and contour integration technique, the spectral response of the normal contact force between the receiving transducer and the wave guide, due to an arbitrary input pulse excited by the transmitting transducer, is expressed as a form of explicitly physical interpretations. Time histories of the response are then obtained through the inversion of the spectra by a fast Fourier transform (FFT) method. Finally, some numerical results are presented in diagrams, from which the effects on the mass of the receiver, the distance between the two transducers, and the input pulse width on the output are discussed. From the numerical calculation and the nature of the whole analysis it is shown that the analytical method presented in this paper is not only effective but also extendible to the more general cases.

研究了接触式超声发射与接收换能器在以Timo-shenko梁为波导元件时的输入-输出特性。借助于多重积分变换方法及围线积分技术,获得了发射器输入任意脉冲时接收换能器与波导之间接触力的频谱显式表达式,然后利用快速傅里叶变换方法得到了其时间历程响应。最后通过数值分析讨论了换能器质量、相互之间的距离以及输入脉冲的宽度对输出响应的影响。计算表明,本方法是有效的。