Three-dimensional crack growth modelling of a Ni-based superalloy at elevated temperature and sustained loading

Storgärds, Erik; Simonsson, Kjell; Sjöström, Sören

doi:10.1016/j.tafmec.2015.11.008

Cited by 15 publications

(5 citation statements)

References 26 publications

(42 reference statements)

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“…Experimental studies were carried out to assess this damaged zone [19,20]. This concept is also used in crack growth models to assess fatigue-creep-environment interactions [21][22][23][24]. With these analyses, the hold-time effect is investigated at a fine scale, that is the volume of material surrounding the crack tip affected by environmental, and mechanical damage.…”

Section: Introductionmentioning

confidence: 99%

Relation between crack growth behaviour and crack front morphology under hold-time conditions in DA Inconel 718

Fessler

Andrieu

Bonnand

et al. 2017

International Journal of Fatigue

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OATAO is an open access repository that collects the work of Toulouse researchers and makes it freely available over the web where possible. This is an author-deposited version published in : http://oatao.univ-toulouse.fr/ Eprints ID : 18105To link to this article : a b s t r a c tThe crack growth behaviour of Direct Aged Inconel 718 was studied at 550°C. Experiments were carried out under pure fatigue cycles, hold-time cycles of different durations and a mix of both. Hold-time cycles were systematically associated with complex crack front morphologies. A new numerical approach was developed to assess the effect of crack front morphology on the direct current potential drop technique, mechanical fields at the crack tip and ultimately, measured crack growth rates. Using this approach, a clear relation was established between crack front morphology and its evolution, and the crack growth behaviour under hold-time conditions. Complex crack front morphologies are demonstrated to be responsible for increased crack growth rates. From this, a crack growth mechanism under hold-time conditions is proposed. Finally, the numerical framework here presented is to be considered as a new, easily reproducible, way to properly analyse experimental data when dealing with complex loading cycles and complex crack front morphologies.⇑ Corresponding author at: Safran Aircraft Engines, établissement de Villaroche,

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Section: Introductionmentioning

confidence: 99%

Relation between crack growth behaviour and crack front morphology under hold-time conditions in DA Inconel 718

Fessler

Andrieu

Bonnand

et al. 2017

International Journal of Fatigue

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“…This is due to the fact that the constraints, which depend on the stress state, are different at the surface and in the specimen interior [17]. Such behaviour, is generally more pronounced under conditions resulting in intergranular cracking [18][19][20][21]. Branco et al [19] observed that during sustained load crack propagation tests the introduction of side grooves, which enhance the plane strain condition of CT-specimens, increase the time dependent crack propagation rate.…”

Section: Introductionmentioning

confidence: 99%

Anisotropy effects during dwell-fatigue caused by δ-phase orientation in forged Inconel 718

Saarimäki

Colliander

Moverare

2017

Materials Science and Engineering: A

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A B S T R A C TInconel 718 is a commonly used superalloy for turbine discs in the gas turbine industry. Turbine discs are often subjected to dwell-fatigue as a result of long constant load cycles. The effect of anisotropy on dwell-fatigue cracking in forged turbine discs have not yet been thoroughly investigated. Crack propagation behaviour was characterised using compact tension (CT) samples cut in different orientations from a real turbine disc forging. Samples were also cut in two different thicknesses in order to investigate the influence of plane strain and plane stress condition on the crack propagation rates. The samples were subjected to dwell-fatigue tests at 550°C with 90 s or 2160 s dwell-times at maximum load. Microstructure characterisation was done using scanning electron microscopy (SEM) techniques such as electron channelling contrast imaging (ECCI), electron backscatter diffraction (EBSD), and light optical microscopy (LOM). The forged alloy exhibits strong anisotropic behaviour caused by the non-random δ-phase orientation. When δ-phases were oriented perpendicular compared to parallel to the loading direction, the crack growth rates were approximately ten times faster. Crack growth occurred preferably in the interface between the γ-matrix and the δ-phase.

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“…Based on the M-integral, a more representative stress intensity factor (SIF) solution is provided by FRANC3D to assess crack propagation life, crack propagation path, fracture, and fatigue life, which has been proven very successful in many respects. [12][13][14][15] The fatigue fracture process of high-strength bolts is generally separated into three stages, namely, crack initiation at the bottom of the thread, crack stable propagation along the root of the thread, and rapid fracture stage. The first two stages can basically be considered as the entire bolt life cycle.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Numerical simulation and experimental verification of fatigue crack propagation in high-strength bolts based on fracture mechanics

Zhang,

Li,

Zhao

et al. 2023

Science Progress

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To investigate the fatigue crack propagation behavior of high-strength bolts for high-speed train brake discs, the fatigue crack propagation of high-strength bolts with initial defects under various load ratios was numerically simulated and experimentally verified based on fracture mechanics in this paper. Firstly, the fracture mechanics model of a three-dimensional hexahedral mesh with initial root defects was established using ABAQUS-FRANC3D interactive technology. Then the stress intensity factor (SIF) of the crack front was calculated by the stress superposition of the crack surface to simulate the coupling effect of preload and axial cyclic load. Based on it, fatigue crack propagation was simulated. Finally, the corresponding fatigue experiments on prefabricated crack bolts were carried out. The results show that mode I cracks dominate in the process of crack propagation. The stable crack propagation zones of the fractured high-strength bolts all show a semi-elliptical cross-section. The SIF of the crack front decreases with the increase of the load ratio, thus making the crack propagation life increase with the increase of the load ratio. The experimental outcomes are in great agreement with the simulation results, which verify that the numerical simulation method can effectively and accurately evaluate the fatigue life of high-strength bolts with initial defects and provides an effective means for predicting the fatigue crack propagation life of the same type high-strength bolts in engineering applications.

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Three-dimensional crack growth modelling of a Ni-based superalloy at elevated temperature and sustained loading

Cited by 15 publications

References 26 publications

Relation between crack growth behaviour and crack front morphology under hold-time conditions in DA Inconel 718

Relation between crack growth behaviour and crack front morphology under hold-time conditions in DA Inconel 718

Anisotropy effects during dwell-fatigue caused by δ-phase orientation in forged Inconel 718

Numerical simulation and experimental verification of fatigue crack propagation in high-strength bolts based on fracture mechanics

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