Analysis of Multiaxial Low Cycle Fatigue Life for Single Crystal Ni-Based Superalloy Based on Two-Phase Unit Cell Model

2011 ◽  
Vol 117-119 ◽  
pp. 503-508
Author(s):  
Zhi Ping Ding ◽  
Ming Li ◽  
Teng Fei Wang ◽  
Rong Hua Yang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Single Crystal ◽  
Life Prediction ◽  
Cell Model ◽  
Low Cycle Fatigue ◽  
Element Model ◽  
Unit Cell ◽  
Single Crystal Superalloy ◽  
Two Phase

Based on micro structure of Ni-based single crystal superalloy, a γ/γ’ two-phase unit cell finite element model was established, and its cyclic stress-strain was simulated under tension/torsion cyclic loading. A low cycle fatigue (LCF) life prediction model of single crystal superalloy was proposed by using cyclic plasticity strain energy as a parameter based on energy dissipation theory. Calculation results of macro finite element model and γ/γ’ two-phase unit cell micro finite element model, and multiaxial LCF test data of CMSX-2 Ni-based single crystal superalloy along [001] orientation were applied to fit the LCF life model by multiple linear regression. The results show that the unit cell model not only reflects the microstructure characteristics of single crystal Ni-based superalloy, but also is better than the macro model in accuracy of analysis, and greatly improve the accuracy of fatigue life prediction. Almost test data fall into the factor of 2.0 scatter band.

Proposal of a new low-cycle fatigue life model for cast iron with room temperature calibration involving mean stress and high-temperature effects

2019 ◽  
Vol 233 (14) ◽  
pp. 5056-5073 ◽  
Author(s):  
Cristiana Delprete ◽  
Raffaella Sesana
Keyword(s):  
Finite Element ◽  
Cast Iron ◽  
High Temperature ◽  
Finite Element Model ◽  
Life Prediction ◽  
Low Cycle Fatigue ◽  
Element Model ◽  
Mean Stress ◽  
Exhaust Manifold ◽  
Cycle Fatigue

The paper presents and discusses a low-cycle fatigue life prediction energy-based model. The model was applied to a commercial cast iron automotive exhaust manifold. The total expended energy until fracture proposed by the Skelton model was modified by means of two coefficients which take into account of the effects of mean stress and/or mean strain, and the presence of high temperature. The model was calibrated by means of experimental tests developed on Fe–2.4C–4.6Si–0.7Mo–1.2Cr high-temperature-resistant ductile cast iron. The thermostructural transient analysis was developed on a finite element model built to overtake confidentiality industrial restrictions. In addition to the commercial exhaust manifold, the finite element model considers the bolts, the gasket, and a cylinder head simulacrum to consider the corresponding thermal and mechanical boundary conditions. The life assessment performance of the energy-based model with respect the cast iron specimens was compared with the corresponding Basquin–Manson–Coffin and Skelton models. The model prediction fits the experimental data with a good agreement, which is comparable with both the literature models and it shows a better fitting at high temperature. The life estimations computed with respect the exhaust manifold finite element model were compared with different multiaxial literature life models and literature data to evaluate the life prediction capability of the proposed energy-based model.

scholarly journals The Peierls–Nabarro finite element model in two-phase microstructures – A comparison with atomistic

2020 ◽  
Vol 150 ◽  
pp. 103555
Author(s):  
F. Bormann ◽  
K. Mikeš ◽  
O. Rokoš ◽  
R.H.J. Peerlings
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Two Phase

Towards Truly Multiscale Simulation of Fatigue Processes in Metallic Structures

2009 ◽  
Author(s):  
John M. Emery ◽  
Jeffrey E. Bozek ◽  
Anthony R. Ingraffea
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Boundary Conditions ◽  
Finite Element Model ◽  
Life Prediction ◽  
Element Model ◽  
Multiscale Simulation ◽  
Fatigue Life Prediction ◽  
Length Scale ◽  
Metallic Structures

The fatigue resistance of metallic structures is inherently random due to environmental and boundary conditions, and microstructural geometry, including discontinuities, and material properties. A new methodology for fatigue life prediction is under development to account for these sources of randomness. One essential aspect of the methodology is the ability to perform truly multiscale simulations: simulations that directly link the boundary conditions on the structural length scale to the damage mechanisms of the microstructural length scale. This presentation compares and contrasts two multiscale methods suitable for fatigue life prediction. The first is a brute force method employing the widely-used multipoint constraint technique which couples a finite element model of the microstructure within the finite element model of the structural component. The second is a more subtle, modified multi-grid method which alternates analyses between the two finite element models while representing the evolving microstructural damage. Examples and comparisons are made for several geometries and preliminary validation is achieved with comparison to experimental tests conducted by the Northrop Grumman Corporation on a wing-panel structural geometry.

A two-phase finite element model of the diastolic left ventricle

1991 ◽  
Vol 24 (7) ◽  
pp. 527-538 ◽  
Author(s):  
Jacques M. Huyghe ◽  
Dick H. van Campen ◽  
Theo Arts ◽  
Robert M. Heethaar
Keyword(s):  
Finite Element ◽  
Left Ventricle ◽  
Finite Element Model ◽  
Element Model ◽  
Two Phase

scholarly journals A two-phase Finite Element model for coupled heat flux and water flow in fully saturated soils

PAMM ◽  
2009 ◽  
Vol 9 (1) ◽  
pp. 391-392
Author(s):  
Mengmeng Zhou ◽  
Felix Nagel ◽  
Jens Kruschwitz ◽  
Günther Meschke
Keyword(s):  
Heat Flux ◽  
Finite Element ◽  
Finite Element Model ◽  
Water Flow ◽  
Element Model ◽  
Saturated Soils ◽  
Two Phase

A method for measuring single-crystal elastic moduli using high-energy X-ray diffraction and a crystal-based finite element model

2010 ◽  
Vol 58 (17) ◽  
pp. 5806-5819 ◽  
Author(s):  
C. Efstathiou ◽  
D.E. Boyce ◽  
J.-S. Park ◽  
U. Lienert ◽  
P.R. Dawson ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Single Crystal ◽  
Elastic Moduli ◽  
Element Model ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray

Simulation on Stress Relaxation of DD3 Nickel-Based Single Crystal Superalloy Based on Micro-Cell Model

2013 ◽  
Vol 834-836 ◽  
pp. 1557-1562
Author(s):  
Zhi Ping Ding ◽  
Jun Zeng ◽  
Xiao Peng Bai ◽  
Jian Hui Fang
Keyword(s):  
Stress Relaxation ◽  
Single Crystal ◽  
Cell Model ◽  
Low Cycle Fatigue ◽  
Thin Wall ◽  
Simulation Studies ◽  
Two Phase ◽  
Single Cell Model ◽  
The Matrix ◽  
Accumulation Phenomenon

Tension-torsion experiments at 680°C and 850°C on thin-wall tube specimens of DD3 nickel-based single crystal superalloys were successfully completed. It shows that specimens have stress relaxation obviously and inelastic deformation accumulation phenomenon with different crystal orientation under asymmetric cyclic loadings. Based on the microstructure characteristics of nickel-based single crystal superalloys, a two-phase multi-cell microscopic mechanical model was established by finite element method to simulate the test with displacement. Numerical simulation studies showed that the matrix phase appeared plastic deformation accumulation at first and resulted in low cycle fatigue damage, but stress distortion occurred on the boundary with a single cell model under tension-torsion displacement loading, which is not consistent with experimental results. While using multi-cell model can avoid this phenomenon, it could be better to simulate stress relaxation behavior under asymmetric cyclic loading at elevated temperature and to study on stress weaken damage for single crystal superalloys.

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