【摘要】 燃料棒与支撑格架间的微动磨损（Grid-To-Rod Fretting,GTRF）是导致压水堆燃料棒失效的主要原因，准确预测GTRF是压水堆燃料设计的重要问题。由于影响GTRF的主要因素中普遍存在不确定性，因此本文考虑系统参数的不确定性，研究了含参数不确定性的压水堆燃料棒非线性流致振动及其所致的磨损问题。首先考虑燃料棒与间隙支撑格架之间的相互作用，建立了其在冷却剂中的非线性振动模型。然后分析了系统非线性振动响应特征，并结合Archard磨损模型研究了振动磨损速率的动力学特性。最后考虑燃料棒由于高温、辐照、格架松弛以及初始结构制造公差等因素而导致的模型参数不确定性，基于切比雪夫区间算法开展了磨损速率的不确定性分析。结果表明：燃料棒磨损速率与结构非线性运动状态密切相关；不同的不确定性参数对磨损速率的影响程度不同，更会导致磨损速率的不确定性区间出现显著差异。更多还原

【Abstract】 [Background] Grid-to-rod fretting(GTRF) wear is a predominant mechanism leading to fuel rod failure. Its prediction, subject to considerable uncertainties in operating parameters, remains a persistent challenge. Based on this, given the safety risks of fission product leakage, fretting wear damage is a major concern for nuclear designers. [Purpose] This study aims to develop a nonlinear flow-induced vibration model for nuclear fuel rods with uncertain parameters, to enhance the accuracy of wear prediction under realistic conditions. [Methods] First of all, a nonlinear flow-induced vibration model was developed with consideration of the interaction between fuel rods and support grids. Then, the nonlinear vibration response characteristics of the system were analyzed, and the dynamic characteristics of vibration wear rate were studied with combination of Archard wear model to evaluate fretting wear between the fuel rod cladding and the grid. Finally, the uncertainty of model parameters caused by high temperature, irradiation, grid relaxation and initial structural manufacturing tolerance of fuel rods were taken into account, and the Chebyshev interval method was applied to uncertainty analysis of wear rate arising from high temperature, radiation, and grid relaxation. [Results] The results show that the fuel rod’s wear rate is closely linked to its nonlinear motion behavior. Different uncertainty parameters exert varying degrees of influence on the wear rate, resulting in substantial differences in the width of the uncertainty interval for the wear rate. When the impact stiffness is considered an interval variable, variations in the clearance can lead to a sixfold difference in the width of the uncertainty interval for the wear rate. [Conclusion] The nonlinear vibration model proposed in this study for fuel rods GTRF wear using the Chebyshev interval method for uncertainty analysis offers a theoretical basis for engineering applications.更多还原