Instantaneous frequency analysis of in-plane bending mode of cylindrical shells in buried environment

Abstract

In recent years, the deterioration of water main to be social problem, because of occurrence of water leakage and burst accidents. Owing to prevent the accidents, it is important to condition assessment for water main. In previous work, Non-Destructive Inspection (NDI) based on in-plane bending mode was proposed. However, the previous works were not considered to influence by buried situation. In this paper, the buried situation dependency of in-plane bending mode frequency is considered focused on the instantaneous frequency analysis. As the result, the nonlinear free oscillation behavior was observed in the imitate thinning pipe in buried situation.