Characterization of creep constraint effect for brazed joint specimens at crack tip by new constraint parameter As

[Display omitted] •A new creep constraint parameter As of brazed joint was proposed.•The load independence and fitness of As are superior than those of R* and Ac.•The creep crack growth of brazed joint at different constraint levels are investigated.•The constraint dependent CCG rate equation for brazed joints is established.•The predicted data by proposed equation agree with experiment very well. In this study, a new creep constraint parameter As of brazed joint was proposed based on existing constraint parameters R* and Ac. The proposed parameter As is superior than R* and Ac because the constraint parameter As is not affected by the selection of creep steady time and distance from crack tip. And the load independence of constraint parameter As for different constraint levels are all superior than that of parameter R* and Ac. Based on the relationships between creep crack growth (CCG) rate and constraint parameter predicted by single-material method, the superiority to characterize constraint effect of constraint parameter As is clarified. The CCG rate equation dependent constraint of brazed joints is established based on the defined parameter. The CCG data predicted by established constraint dependent CCG rate equation have a good accordance with experiment. The established CCG rate equation dependent constraint can predict the CCG rate at different constraint levels very well.