埋設環境下における円筒殻の面内曲げ変形振動の解析

抄録

Owing to aging of distribution main, the accident such as leakage and explosion are occurring. To prevent above accidents, it is essential to maintain and manage the system through appropriate renewal and repair. For efficient maintenance and management, it is important to quantify the condition of main by Non-Destructive Inspection (NDI) and reflect it in renewal and repair plans. One of method to maintain the main efficiently, deterioration diagnosis method for distribution main using the eigen frequency of in-plane bending mode in circular cylindrical shell is already suggested. The eigen frequency of in-plane bending mode is expected to have high accuracy in detection of deterioration, because the eigen frequency is proportional to pipe thickness. However, actually main is subjected to ground soil elastic force because of buried situation. In this paper, the in-plane bending oscillation in cylindrical shell which is subjected soil stiffness is systematically considered.