弾性波を利用した鉄筋の腐食推定に関する解析的研究

Abstract

In this study, the applicability of impact wave method to evaluate the steel corrosion was discussed analytically. Following results were obtained in this study : 1) The undershot phenomenon is observed in the case of h (coefficient of damping) ≐̸0,but does not in the case of h=0. The relationship between the propagation velocity of reflection wave and the passing time from the input of impact wave is very affected by the value of coefficient of damping. 2) The sign of propagation velocity of elastic wave reflected from the bottom of steel bar is changed by the boundary condition of steel bar, namely a free end or a fixed end. But the wave propagation characteristics is hardly affected by the boundary condition of steel bar in the range before the arrival time of wave reflected from the bottom of steel bar. 3) The steel corrosion can be estimated by the arrival time of wave reflected from the corrosion point and its amplitude of propagation velocity, but it is necessary to take into the account the effect of multi deflection of elastic wave, so as to improve the accuracy of estimation.