Characterization of 3-D creep constraint and creep crack growth rate in test specimens in ASTM-E1457 standard

Three-dimensional creep constraint of six specimen geometries in ASTM E1457 standard was characterized by using two constraint parameters, and creep crack growth (CCG) rates in these specimens were predicted by using numerical simulations. The results show that the specimens with different geometries and size ranges recommended by ASTM-E1457 have different constraints, thus produce different CCG rate data. With increasing specimen thickness and side-groove depth, the constraint and CCG rates of all specimens increase. It needs to consider constraint effects on CCG rate when predicting component life using laboratory data. The quantitative correlation formulas of CCG rate with creep constraint have been established.