反应堆压力容器承压热冲击概率断裂力学分析

Analysis of Probabilistic Fracture Mechanics for PTS of Reactor Pressure Vessel

在反应堆过冷瞬态下,沿壁厚范围内的温差将引起很大的热应力,在反应堆压力容器(RPV)内壁产生较高的拉应力,再加上内压的作用,内表面缺陷有可能迅速扩展甚至贯穿壁厚。本文采用概率断裂力学基本理论,考虑各参数的不确定性因素,在明确各参数随机分布特征的基础上,利用Monte Carlo法通过程序产生相应的随机数,然后依据断裂力学评定准则建立功能函数,最后完成可靠性数据的统计计算并给出失效概率。

In over-cooling transient of reactors,the difference in temperature along the RPV wall will cause a large thermal stress,and then will generate a high tensile stress.Coupled with the internal big pressure,the defects in the inner surface of the RPV will propagate rapidly and even through the thickness.The probabilistic fracture mechanics theories were used in this paper.The uncertainty factors of the parameters were considered.The random numbers were generated using the Monte Carlo method on the basis of the random distribution of the parameters firstly,and then the limit function was established according to the fracture mechanics assessment criteria.Finally the failure probability was obtained by statistic calculation of the reliability data.