Prediction of creep crack growth behavior in ASME P92 steel welded joint

Two-parameter characterization of constraint effect induced by specimen size on creep crack growth

“…The parameter C ⁄ is calculated from the load line displacement rate obtained from FEM results according to Eq. (5), which is the same with the method employed in the experiments [31,33,36]. As shown in Fig.…”

“…Because the node releasing technique could virtually represent the actual crack propagation compared with other prevail approaches, which had been widely used to simulate the creep crack growth and had been certified that the calculated results could match well with the corresponding experimental results [31][32][33]. However, this technique was hard to be achieved in 3D FE analyses.…”

“…In this model, an uncoupled single damage parameter is introduced. The rate of the creep damage accumulation depends on the equivalent creep strain rate ( _ e c ) and can be written as follows [32,33]:…”

“…The typical creep curve is always composed of the primary, secondary and tertiary creep stage. In order to describe all three stages of the creep curve, an average creep strain rate is employed and is defined by the ratio of the uniaxial failure strain (e f ), to the rupture time in a uniaxial creep test (t r ) [32,33]:…”

“…The total damage at any time is calculated from the time integral of creep damage accumulation rate [32,33]:…”