Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : June 17, 2024 - June 18, 2024
Unnecessary plant shutdowns are avoided using the cumulative absolute velocity (CAV) on the nuclear power plant’s free-field seismic instrumentation to determine operating basis earthquake in the US; however, the relationship between the CAV and damage mechanism has not yet been clarified. In a previous study, authors found that the CAV of the piping vibration response can relate to the vibration stress, using the velocity rule from the ASME standard for the Operation and Maintenance (OM) of Nuclear Power Plants. Using the velocity rule, a new evaluation method of cumulative fatigue damage can be derived as proportional to CAV of the vibration response to the 2.4th power. In this study, the Z-bend pipeline is considered to confirm the applicability of the new method based on the velocity rule to more general pipelines. The vibration response of the Z-bend pipeline to seismic waves was calculated, and the cumulative fatigue damage was evaluated using both the new method and direct calculations. The results were in good agreement.
