Deterministic and probabilistic creep–fatigue–oxidation crack growth modeling

The general scheme of crack growth modeling and periodicity of aviation structure elements checks was developed. The major factors determined the scale of inaccuracy calculation ( εN*) based on calculations of crack growth duration (N*) and inspections intervals (τ0) were marked and estimated with the block diagram.

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Thermomechanical Fatigue Crack Growth Modeling in a Ni-Based Superalloy Subjected to Sustained Load

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4031158 ◽

2015 ◽

Vol 138 (1) ◽

Cited By ~ 1

Author(s):

Erik Storgärds ◽

Kjell Simonsson ◽

Sören Sjöström ◽

Johan Moverare

Keyword(s):

Crack Growth ◽

Damage Model ◽

Growth Modeling ◽

Maximum Load ◽

Thermomechanical Fatigue ◽

Parameter Determination ◽

Sustained Load ◽

Notched Specimen ◽

Number Of Cycles ◽

Crack Growth Modeling

Thermomechanical fatigue (TMF) crack growth modeling has been conducted on Inconel 718 with dwell time at maximum load. A history dependent damage model taking dwell damage into account, developed under isothermal conditions, has been extended for TMF conditions. Parameter determination for the model is carried out on isothermal load controlled tests at 550–650 °C for surface cracks, which later have been used to extrapolate parameters used for TMF crack growth. Further, validation of the developed model is conducted on a notched specimen subjected to strain control at 50–550 °C. Satisfying results are gained within reasonable scatter level compared for test and simulated number of cycles to failure.

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A New Linear Superposition Theory and its Application in Creep Fatigue-Oxidation Crack Growth Modeling

Volume 6: Materials and Fabrication, Parts A and B ◽

10.1115/pvp2012-78230 ◽

2012 ◽

Cited By ~ 5

Author(s):

Zhigang Wei ◽

Fulun Yang ◽

Burt Lin ◽

Limin Luo ◽

Dmitri Konson ◽

...

Keyword(s):

Crack Growth ◽

Growth Models ◽

Worked Examples ◽

Damage Mechanism ◽

Turbine Engines ◽

Linear Superposition ◽

Creep Fatigue ◽

Growth Laws ◽

Cycle Dependent ◽

Crack Growth Modeling

Fatigue, creep, oxidation or their combinations have long been recognized as the principal mechanisms in many high-temperature failures in power plant components, turbine engines, and exhaust systems in vehicles. Depending on the specific materials and loading conditions and temperature, the role of each damage mechanism may change significantly, ranging from independent development to competing and combined creep-fatigue, fatigue-oxidation, and creep-fatigue-oxidation. In this paper a new linear superposition theory is proposed to model the cycle-dependent and time-dependent creep-fatigue-oxidation crack growth phenomena. The model can be reduced to creep-fatigue and fatigue-oxidation crack growth models previously developed by the authors as well as, under some assumptions, the current widely used linear superposition theory. The limits of the current superposition theory and the advantages of the new theory are clearly demonstrated with several worked examples. A general probabilistic analysis procedure is also proposed by introducing the uncertainties of parameters in fatigue, creep, and oxidation crack growth laws with the help of the Monte Carlo simulation.

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