RPV PTS分析中二次应力塑性修正因子ρ的精确值

摘要

根据R6规范第四版Ⅲ．3．3．1节内容，推导出一种二次应力塑性修正因子ρ的精确计算方法。有限元计算出了某反应堆压力容器（RPV ）在承压热冲击（PTS ）瞬态时的ρ精确值，并用以分析了R6规范第Ⅰ章基本方法中ρ因子的保守性程度，讨论了ρ因子保守性对结构安全裕量（SM）的影响。研究结果表明，本文的分析案例中，R6规范第Ⅰ章基本方法中ρ因子的保守程度均在20％以上，由此引起断裂韧性SM的保守性也均在4％以上，并且断裂韧性SM的保守性随裂纹前沿温度的增加而增大。因此，当希望利用失效评定图（FAD）获得结构SM的精确评定时，有必要有更精确的ρ因子解。%Based on the ChapterⅢ.3.3.1 of the revision 4 of R6 code,an accurate method for calculat-ing the value of the secondary stress plasticity correction parameter ρwas induced.This paper presented the finite element accuracy solutions of theρfactors and the conservation of parameterρin the ChapterⅠof the R6 code(basic procedures)under the pressurized thermal shock(PTS)condition of a reactor pres-sure vessel(RPV),and the conservation of the safety margin(SM)of the structure was also evaluated.It has been found that the conservation of its correction parameters ρis above 20%,and the conservation of the fracture toughness SM is more than 4%.The conservation of the fracture toughness SM increases with increasing the temperature of the crack tip.As a result,it′s necessary to get more accurate plasticity cor-rection ρfor the accurate assessment of the failure assessment diagram(FAD)method.