creep damage

thermal fatigue

thermal fatigue
Stages of thermal fatigue or blade creep on a typical turbine blade. In the primary stage the initial rate of creep decreases rapidly, in secondary stage the rate decreases more slowly or may be substantially constant and in tertiary stage, the rate increases rapidly and leads eventually to fracture.
A kind of metal fatigue caused by repeated heating and cooling. It is prominent in turbines where some heating or cooling takes place each time a power setting is changed. Also called creep damage. See also creep (ii).
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References in periodicals archive ?
A Review of Methods to Estimate Creep Damage in LowAlloy Steel Power Station Steam Pipes", STRAIN, 45: 316-331, ISSN: 0039-2103.
Electromagnetic acoustic resonance to assess creep damage in Cr-Mo-V steel, Japan Soc.
Liu, "Study of creep damage constitutive relation of granite considering thermal effect," Chinese Journal of Rock Mechanics and Engineering, vol.
These inspections are largely targeted at detecting late stage creep damage in which cracking is active in the component and provides qualitative rather than quantitative data.
Permanently installed monitoring of creep damage (Imperial College) a Non-linear material inspection (University of Bristol)
Operating at low frequencies reduced the self-healing effect and the effects of creep damage.
As is expected, majority of these failures had creep damage as the primary mode of failures.
The topics include the time-temperature-age superposition principle for predicting the long-term response of linear viscoelastic materials, predicting the viscoelastic behavior of polymer nano-composites, fiber-bundle models to analyze creep rupture in polymer matrix composites, the continuum-damage mechanical modeling of creep damage and fatigue, accelerated testing methodology for predicting long-term creep and fatigue, and monitoring the structural health of composite structures for durability.
By the late 1990's it was becoming better understood that creep damage in seam welds did not initiate as distinctive crack-like flaws, but rather as an accumulation of microstructural damage evidenced by "cavitation" development around inclusions and carbides along the grain boundaries in the heat affected zone or fusion zone of the seam weld (depending on whether the structure was normalized and tempered or subcritically annealed after welding).
Though slipped deadlines, blown budgets and feature creep damage the bottom line, organizations often are reluctant to mess with their project processes," says Ben Snyder, Systemation's CEO.