高频超声在变幅杆件中传播损耗的测试

应用2.5 MHz超声探头,在两组不同尺寸阶梯形变幅杆中获得了相同测试条件下的超声回波信号.再利用数字示波器对信号进行采样,得到了数字化超声回波时域信号.根据傅里叶变换理论,得出了回波信号的波形和功率谱图,进而发现超声能量在这些不同尺寸变幅杆中谐振频率附近传播衰减的规律.结果表明,变幅杆放大系数大,从一端传递到另一端的平均声能量密度大.超声在阶梯形变幅杆中传播,其谐振频率附近回波功率谱线幅度与变幅杆几何尺寸有关.

The test of transmission losses of high frequency ultrasound in solid horn

Transmission losses in two different size groups of step-bar ultrasonic solid horn are tested by using 2.5MHz ultrasonic transducer,and the ultrasonic echoes are attained under the same test condition.The time domain ultrasonic echoes are sampled with digital oscilloscope.And then,on the basis of the Fast Fourier Transform(FFT) theory,the signal of ultrasonic echoes and the power spectrum are attained.After comparison and analysis,the preliminary patterns of ultrasonic energy transmission losses in the solid horns at their resonance frequency are gained.Furthermore,the hypostasis of magnification factor of a solid horn is explained.The method of ultrasonic energy transmission losses in more complex and different type solid horns is offered in this paper.