火电厂耐热钢的非线性局部化蠕变损伤研究

Research on Non-linear Localized Creep Damage of Heat Resistant Steel in Heat Power Plants

针对火电厂中蒸汽管道与汽包一类承压部件常用耐热钢材 ,在经历长时间高温高压作用后 ,处于蠕应变Ⅲ阶段过程时 ,发生非线性局部化 (大变形 )蠕变损伤问题 ,给出损伤本构描述 ,提出非线性局部化蠕变损伤本构模型及其数值变分原理与有限元离散化形式 。

In the light of the fact that nonlinear localized creep damage happens to common heat resistant steel used as pressure elements like steam pipeline and steam pockets in the third stage of creep strain, this article shows the constitutive model of nonlinear localized creep damage, its numerical variation principle and finite element discretization form, thus introducing another theory of elasticoplastic creep damage and a new numerical variational medthod.