The use of failure assessment diagrams (FAD) for evaluating the integrity of components containing crack-like flaws has developed a well-defined methodology over the years that includes a correction factor to account for combined loading effects that are a result of primary and secondary stresses. The load combination factor, Ψ, is based on the Option 1 FAD currently in use in the Central Electricity Generating Board's (CEGB) report No. R/H/R6 (R6) and the API-579-1/ASME FFS-1 fitness-for-service standard. The Ψ factors for the Option 2 FAD based on ASME B&PV Code Section VIII, Division 2 material stress-strain curves are developed and tabulated here for a wide range materials used for the construction of pressure vessels. The Ψ factors based on the Option 1 FAD are recalculated here and compared to current published data. The approach utilizing Option 1 FAD methods is evaluated here with regard to its conservatism and applicability to material models other than the Ramberg-Osgood model. In addition, a sensitivity analysis is performed to estimate Ψ factor errors due to uncertainty in material property parameters. A critical review of the tabulated data in API-579 is performed and errors are identified along with suggested solutions to correct the data.
| File Size : | 1
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| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 204 |
| Published : | 2014 |
