Study on Nonlinear Flow-Induced Vibration Wear of Fuel Rods in Pressurized Water Reactors under Parameter Uncertainty

Firstly, considering the interaction between the fuel rod and the gap support lattice, a nonlinear vibration model of it in the coolant was established. Then, the nonlinear vibration response characteristics of the system were analyzed, and the dynamic characteristics of vibration wear rate were studied by combining the Archard wear model.

Finally, considering the uncertainty of model parameters caused by factors such as high temperature, irradiation, lattice relaxation, and initial structural manufacturing tolerances of fuel rods, an uncertainty analysis of wear rate was conducted based on the Chebyshev interval algorithm. The results indicate that the wear rate of fuel rods is closely related to the nonlinear motion state of the structure; Different uncertainty parameters have varying degrees of impact on the wear rate, leading to significant differences in the uncertainty range of the wear rate.