NUMERICAL PREDICTION OF CONSTRAINT EFFECT OF CREEP CRACK GROWTH

This paper presents the effect of constraint on creep crack growth (CCG) using FE analysis based on the stress and strain rate state at the crack tip. The comparison is made by modelling C(T) specimen tests under plane stress and plane strain conditions using creep properties of three different steels (C-Mn steel, P91 steel, and 316H austenitic steel). In addition, in order to examine the constraint effect on CCG due to geometry single edge notch specimen (SENT), centre cracked tension specimen (CCT) and three point bending (3PB) specimen have also been analysed. In all cases it is found that when the reference stress under plane strain conditions is higher than the yield stress, there is little difference between CCG rates under plane stress and plane strain.