コンクリート中の鋼材を長手方向に伝搬する弾性波のモデル化と実験的検証

抄録

This study presents a fundamental investigation toward quantitative nondestructive testing for steel bars in concrete, based on elastic waves. The propagation characteristics of leaky guided waves in a steel bar embedded in concrete were analyzed using the semi-analytical finite element (SAFE) analysis. The SAFE formulation was conducted in cylindrical coordinates, incorporating the radiation condition of the surrounding concrete. The dispersion curve showed that the energy velocity of the longitudinal (L) mode increases with frequency and asymptotically approaches the bulk L-wave velocity of steel. While the L-mode waves in embedded bars exhibited attenuation due to leakage into the concrete, higher-frequency components showed less attenuation compared with lower frequencies.