配管系の動的強度評価法に関する基礎研究,4; 振動疲労破壊時のエネルギーと破壊の関係

Study on dynamic strength evaluation method of piping systems, 4; Relationship between energy and fracture on vibration fatigue fracture

皆川 佳祐*; 藤田 聡*; 北村 誠司 ; 岡村 茂樹

Minagawa, Keisuke*; Fujita, Satoshi*; Kitamura, Seiji; Okamura, Shigeki

本研究では配管系の地震時強度評価手法としてエネルギー釣合式に着目した手法を提案し、その有効性を検討している。本報では、第3報で行った振動疲労破壊実験の結果を、単位時間あたりの総エネルギー入力増加量や入力加速度レベルに着目して整理し、疲労破壊とエネルギーの関係を検討したので報告する。

Mechanical structures installed in nuclear power plants such as piping are usually designed staically in elastic region. Although these mechanical structures have sufficient seismic safety margin, comprehending the ultimate strength is very important in order to improve of the seismic safety reliability in unexpected severe earthquake. The ultimate strength of piping is investigated from the viewpoint of energy balance method in this research. Vibration fracture experiments that lead one mass model to fatigue fracture are carried out in order to investigate the relationship between input energy and fracture.