| 摘要 |
PURPOSE:To determine the viscoelasticity characteristic at each frequency, by making a sound wave incident upon the surface of material to be measured while the reflected wave is detected to determine the viscoelasticity of the material being measured from the amplitude and the cycle of the reflected wave spectrum detected. CONSTITUTION:When a sound wave of a waveform function A(t) is made incident upon a material A to be measured, the reflected waves I1(t) and I2(t) from the interface A/B with material B can be expressed by a function obtained by multiplying the incident wave A(t) by multiplying the damping coefficient K in the material A and the reflection coefficient RAB at the interface A/B while being corrected inn the phase by the reflection frequency. The theoretical frequency spectrum can be obtained by Fourier transform of the reflection wave signal detected. Thus, the damping characteristic of the material being measured is determined from the analysis of the amplitude and the sound velocity (elastic modulus) of the material being measured from the analysis of the cycle as the function of the frequency. |
