基于瞬态分析的浮动核电站高能管路冲击疲劳寿命评估

目的合理评估浮动核电站高能管路在水下冲击载荷下的疲劳寿命。方法开展高能管路静载、模态和瞬态响应分析,得到管路在水下冲击作用下的应力时程曲线,为管路疲劳寿命估算提供基本应力谱输入。基于冲击疲劳损伤模型,运用nCode疲劳分析软件,估算管路的冲击疲劳寿命。结果管路在一次冲击载荷作用下会经历多次应力循环,最大应力值超过材料屈服极限的11%。管路在横向冲击作用下的冲击疲劳寿命为3.95×10~4次。结论管路在冲击载荷作用下的最大应力响应发生在冲击输入的正向三角波之后,反向三角波之内,是由于惯性效应造成的响应滞后现象。管路固定端、弯头和三通是应力集中区域,管路疲劳破坏一般发生在这些局部区域。

Fatigue Life Assessment for High-energy Pipe of Floating Nuclear Power Station under Shocking Based on Instantaneous Analysis

Objective To estimate the fatigue life of high-energy pipes in floating nuclear power station under underwater impact. Methods The static response, mode shapes and dynamic response of the high-energy pipe were predicted to obtain the stress history of the pipe under underwater impact to provide basis stress spectrum import of the fatigue analysis. Based on the fatigue damage model, the impact fatigue life of the pipe was estimated with the aid of the FE-based fatigue analysis program nCode. Result The pipe stress would experience a number of cycles and the maximum stress exceeded the material yield limit by 10% during underwater impact. The impact fatigue life of the pipe under transverse impact was 3.95?104. Conclusion The maximum stress response occurs after the positive triangular wave and in the negative triangular wave of the impact load. It is a response lag phenomenon caused by the effect of inertia. The stress concentration region is located at the fixed end, elbow and tee branch. The fatigue rupture of pipe usually occurs in this region.