Abstract
This paper outlines the procedure and its background philosophies. The ductility exhaustion approach is used to assess creep damage and a short crack growth concept is used to assess fatigue damage. The fatigue cycles are assessed using the Rankine strain range, rather than the von Mises equivalent strain range. Use of a crack growth concept to assess fatigue damage permits the extension of the methodology to cover the effects of thermal striping, which are treated by consideration of fatigue crack growth thresholds. The overall procedure also employs a L-shaped creep-fatigue interaction diagram that differs from those used in other procedures. This is based on an understanding of the interaction of creep and fatigue damage mechanisms and the results of creep fatigue endurance tests covering a range of conditions.
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