基于应变与加速度响应的核电厂小支管振动评价

Vibration Evaluation of Small Bore Pipe in NPPs Based on Strain and Acceleration

核电厂存在大量的仪表管、取样管、排气管等小支管,其机械振动疲劳断裂是商业运行核电厂经常出现的问题。本文以阳江核电站二号机组GRE023管线的实测振动应力对其振动疲劳寿命进行了评价,采用有限元方法以加速度时程二次积分获得的位移时程为输入对其振动疲劳寿命进行了分析,获得了小支管振动疲劳瞬态动力分析关键参数设置方法,同时也为类似结构的减振改造设计积累了经验,为核电厂小支管振动治理提供了参考。

Small bore pipes, existing in a form of large quantities of instrument pipes, sampling pipes and vent pipes, often suffer mechanical vibration fatigue fracture. Vibration fatigue life is evaluated according to measured vibration stresses for GRE023 pipes in Unit 2 of Yangjiang NPP. Measured acceleration time history were double integrated into the displacement time history for vibration fatigue life analysis by finite element method, and key parameters for transient dynamic analysis were also determined, which lays an empirical foundation for vibration reduction of analogical structure. The analytical method can provide a reference for small bore pipe vibration reduction in NPPs.