A Method for Vibration Stress Measurement and Fatigue Life Evaluation of Small Piping in Nuclear Power Plant

Abstract

The invention provides a method for measuring vibration stress and evaluating fatigue life of a small pipeline in a nuclear power plant, comprising the steps of: S1, installing a plurality of displacement sensors arranged at intervals along its axial direction on the pipeline, each of which is used as a measurement point ; S2, obtain the vibration displacement value of the measuring point through the displacement sensor, and use the Pythagorean theorem to calculate the curvature radius of the pipeline vibration deformation at the current moment according to the horizontal position information of the measuring point; S3, obtain the structural parameters of the pipeline to be measured, and according to the Structural parameters and radius of curvature calculate the bending stress of the pipeline vibration at the current moment; S4. Obtain the real-time vibration displacement value and its frequency information of any measurement point through the displacement sensor, and use the Miner linear accumulation theory to calculate the linear cumulative damage of pipeline vibration, and calculate the remaining lifespan. The invention adopts the non-contact measurement method, realizes the rapid calculation of the vibration bending stress and the fatigue life of the pipeline, and has good technical effect.

Description

technical field [0001] The invention relates to the technical field of nuclear power plant pipeline stress analysis, in particular to a method for measuring vibration stress and fatigue life assessment of small nuclear power plant pipelines. Background technique [0002] Due to the long-term high-temperature and high-pressure working conditions of nuclear power plant pipelines, fatigue damage is prone to occur under the action of internal and external loads, which may lead to pipeline cracking, fluid leakage in the pipeline, and even pipeline fracture. Small pipes (less than 3 inches in outer diameter) are high-incidence areas for fatigue failure events due to their large number, complex structure, and wide distribution. In order to ensure the safe operation of the pipeline, it is necessary to reasonably predict its service life and even optimize and improve the design scheme. One of the key measures is to obtain the vibration stress of the pipeline. Therefore, a reasonable ...

AI Technical Summary

Problems solved by technology

[0006] Aiming at the problems of high radiation and high temperature in the vibration stress measurement of pipelines in the prior art, the present invention provides a method for vibration stress measurement and fatigue life evaluation of small nuclear power plant pipelines, which can measure the vibration displacement value and frequency information of the pipeline, thereby Realize the rapid calculation of pipeline vibration stress and mechanical fatigue life

Images