2次元多孔性媒質モデルにおけるS波の散乱について

Abstract

The effects of S-wave scattering by regularly distributed small-scale scatterers on the waveform of S waves and the amplitude level of S coda are investigated by ultrasonic model experi-ments. In the experiments, P and SV pulses radiated simultaneousely from piston-type emitterare used, and the property of S-wave scattering is compared with that of P-wave scattering andis discussed. The variances of spatial amplitude fluctuations of each phase within the durationof S waves strongly depend on the frequency of S waves, and the later the phase arrives, the largerits variance becomes. The logarithmic amplitude ratio of S coda to direct S pulse also stronglydepends on the frequency of S waves. These properties are also observed in the case of P-wavescattering, but the effect of S-wave scattering appears more sensitively than that of P-wave scat-tering because the wave length of S waves is shorter than that of P waves in the case of the samefrequency.