ASME許容振動速度基準の考え方を使った配管耐震疲労評価

抄録

Considering the vibration velocity criterion in the ASME OM code, it was shown that the CAV in each cycle corresponds to the stress amplitude since the CAV in each cycle corresponds to the vibration velocity amplitude. From this, a method was developed, which can calculate stress amplitude from CAV per cycle and calculate cumulative fatigue damage value from Miner's law. The vibration response of the cantilever piping was calculated for four earthquakes, the cumulative fatigue damage value was calculated using the rain flow method, and the results were compared with the developed method to confirm the performance. Both results agreed well. According to the method developed in this paper, when there are a lot of pipes of various shapes with different natural frequencies, it has been shown that the cumulative fatigue damage value of each pipe element is lowered by -2.39th power of the frequency as a general tendency. This suggests that the effect of the acceleration excitation with a high frequency component can be small.