Influence Analysis of Multifactor on LCF Damage of Single Crystal Nickel-Based Superalloy under Multiaxial Non-Proportional Loading

2010 ◽  
Vol 139-141 ◽  
pp. 198-204
Author(s):  
Zhi Ping Ding ◽  
Ji Ping Chen ◽  
Teng Fei Wang ◽  
Ming Li
Keyword(s):  
Single Crystal ◽  
Fatigue Damage ◽  
Phase Angle ◽  
Strain Path ◽  
Biaxial Tension ◽  
Low Cycle Fatigue ◽  
Strain Range ◽  
Cycle Fatigue ◽  
Nickel Based Superalloy ◽  
Strain Paths

A formula of equivalent strain for FCC single crystal superalloy was derived based on Hill’s yield criterion and was used for design of biaxial tension-torsion strain paths and loading levels of specimens. biaxial tension-torsion non-proportional cyclic loading process for single crystal nickel-based superalloy at the temperature of 680°C and 850°C was simulated by FEM analyzes; and influence degree of factors, such as strain range, strain path angle, tension-torsion loading phase angle, cycle characteristics and temperature etc., to low cycle fatigue damage of single crystal nickel-based superalloy were analyzed by using analysis of variance based on orthogonal experiments. The results show that if Hill’s equivalent stress range is used as a fatigue damage parameter, the factors produce effects on low cycle fatigue damage of single crystal nickel-based superalloy. The factors are listed in the order of significance as followed: temperature, strain range, tension-torsion loading phase angle, strain path angle and axial loading strain ratio.

Low Cycle Fatigue Life of Type 316 Stainless Steel Notched Specimen Under Proportional and Non-Proportional Multiaxial Loadings

2010 ◽  
Author(s):  
Takamoto Itoh
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Strain Path ◽  
Low Cycle Fatigue ◽  
Cycle Fatigue ◽  
Notched Specimen ◽  
Life Estimation ◽  
316 Stainless Steel ◽  
Strain Parameter ◽  
Strain Paths

This study discusses multiaxial low cycle fatigue life of notched specimen under proportional and non-proportional loadings at room temperature. Strain controlled multiaxial low cycle fatigue tests were carried out using smooth and circumferentially notched round-bar specimens of type 316 stainless steel. Four kinds of notched specimens were employed of which elastic stress concentration factors, Kt, are 1.5, 2.5, 4.2 and 6.0. The strain paths include proportional and non-proportional loadings. The former employed a push-pull straining or a reversed torsion straining. The latter was achieved by strain path where axial and shear strains has 90 degree phase difference but their amplitudes is the same based on von Mises’ criterion. The notch dependency of multiaxial low cycle fatigue life and the life estimation are discussed. The lives depend on both Kt and strain path. The strain parameter for the life estimation is also discussed with the non-proportional strain parameter proposed by the author with introducing Kt. The proposed parameter gives a satisfactory correlation with multiaxial low cycle fatigue life of notched specimen of type 316 stainless steel under proportional and non-proportional loadings.

scholarly journals Effects of Crystal Orientations on the Low-Cycle Fatigue of a Single-Crystal Nickel-Based Superalloy at 980 °C

2018 ◽  
Vol 32 (3) ◽  
pp. 381-390 ◽  
Author(s):  
Liu Liu ◽  
Jie Meng ◽  
Jin-Lai Liu ◽  
Hai-Feng Zhang ◽  
Xu-Dong Sun ◽  
...  
Keyword(s):  
Single Crystal ◽  
Low Cycle Fatigue ◽  
Cycle Fatigue ◽  
Nickel Based Superalloy ◽  
Crystal Orientations

scholarly journals Low-Cycle Fatigue Behaviour of a Ni-Based Single-Crystal Superalloy

2014 ◽  
Vol 891-892 ◽  
pp. 416-421 ◽  
Author(s):  
Mikael Segersäll ◽  
Johan Moverare ◽  
Daniel Leidermark ◽  
Kjell Simonsson
Keyword(s):  
Single Crystal ◽  
Low Cycle Fatigue ◽  
Strain Range ◽  
Cyclic Hardening ◽  
Fatigue Behaviour ◽  
Single Crystal Superalloy ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Stress Strain ◽  
Tension Compression Asymmetry

In this study, low-cycle fatigue (LCF) tests at 500 °C in the <001>, <011> and <111> directions have been performed for the Ni-based single-crystal superalloy MD2. All tests were carried out in strain control with Rε=-1. The <001> direction has the lowest stiffness of the three directions and also shows the best fatigue properties in this study followed by the <011> and <111> directions, respectively. It is well recognised that Ni-based single-crystal superalloys show a tension/compression asymmetry in yield strength and this study shows that a tension/compression asymmetry also is prevalent during LCF conditions. At mid-life, the <001> direction generally has a higher stress in tension than in compression, while the opposite is true for the <011> direction. For the <111> direction the asymmetry is found to be strain range dependent. The <011> and <111> directions show a cyclic hardening behaviour when comparing cyclic stress-strain curves with monotonic stress-strain curves. In addition, the <011> and <111> directions show a serrated yielding behaviour for a number of cycles while the yielding of the <001> direction is more stable.

Fatigue damage characterisation of MarBN steel for high temperature flexible operating conditions

2016 ◽  
Vol 231 (1-2) ◽  
pp. 23-37 ◽  
Author(s):  
EM O’Hara ◽  
NM Harrison ◽  
BK Polomski ◽  
RA Barrett ◽  
SB Leen
Keyword(s):  
High Temperature ◽  
Fatigue Damage ◽  
Low Cycle Fatigue ◽  
Microstructural Analysis ◽  
Strain Range ◽  
Fatigue Behaviour ◽  
Operating Conditions ◽  
Fracture Mechanisms ◽  
Published Data ◽  
Cycle Fatigue

This article is concerned with the high temperature low cycle fatigue behaviour of a new nano-strengthened martensitic-ferritic steel, MarBN. A range of strain-controlled, low cycle fatigue tests are presented on MarBN at 600 ℃ and 650 ℃, and compared with previously published data for a current state-of-the-art material, P91 steel, including microstructural analysis of the fracture mechanisms. A modified Chaboche damage law, incorporating Coffin–Manson life prediction, is implemented within a hyperbolic sine unified cyclic viscoplastic constitutive model. Calibration and validation of the model with respect to the effects of strain-rate and strain-range is performed based on an optimisation procedure for identification of the material parameters. The cyclic viscoplasticity model with damage successfully predicts fatigue damage evolution and life in the cyclically softening materials, MarBN and P91.

scholarly journals Cyclic plasticity and low cycle fatigue damage characterisation of thermally simulated X100Q heat affected zone

2018 ◽  
Vol 165 ◽  
pp. 03002 ◽  
Author(s):  
Ronan J. Devaney ◽  
Heiner Oesterlin ◽  
Padraic E. O’Donoghue ◽  
Sean B. Leen
Keyword(s):  
Fatigue Damage ◽  
Heat Affected Zone ◽  
Early Stage ◽  
Low Cycle Fatigue ◽  
Kinematic Hardening ◽  
Strain Range ◽  
Parent Material ◽  
Cyclic Plasticity ◽  
Cycle Fatigue ◽  
Constitutive Parameters

This paper presents the cyclic plasticity and low cycle fatigue (LCF) damage characterisation of thermally simulated heat affected zone (HAZ) for API 5L X100Q weldments. Microstructures representative of the HAZ for two cooling rates are generated using a Gleeble thermomechanical simulator for manufacture of strain-controlled cyclic plasticity test specimens. The simulated HAZ specimens are subjected to a strain controlled test programme which examines the cyclic effects of strain-range and the tensile response at room temperature. A modified version of the Chaboche rate independent plasticity model, which accounts for early stage damage is implemented to characterise the cyclic plasticity response, including isotropic and kinematic hardening effects. The constitutive parameters are fitted to experimental data using an optimisation procedure developed within a MATLAB code. The measured response of the simulated HAZ specimens is compared to that of the X100Q parent material (PM), and the simulated HAZ is shown to share the early stage fatigue damage behaviour of the PM, but exhibits significantly a higher yield and cyclic strength.

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