Tension-Torsion Multiaxial Low Cycle Fatigue of Mar-M247LC Directionally Solidified Superalloy at Elevated Temperature

1998 ◽  
Vol 120 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Nakao Shirafuji ◽  
Kenji Shimomizuki ◽  
Masao Sakane ◽  
Masateru Ohnami
Keyword(s):  
Elastic Constant ◽  
Low Cycle Fatigue ◽  
Crack Opening ◽  
Equivalent Stress ◽  
Maximum Principal Stress ◽  
Cycle Fatigue ◽  
Directionally Solidified ◽  
Opening Displacement ◽  
Strain Parameter ◽  
Fatigue Data

This paper studies the high temperature multiaxial low cycle fatigue of Mar-M247LC directionally solidified superalloy. Tension-torsion multiaxial low cycle fatigue tests were carried out using Mar-M247LC tubular specimens at 1173K in air. Several multiaxial strain and stress parameters were applied to the experimental data to examine the suitability of the parameters. All the multiaxial strain parameters proposed so far could not successfully correlate the multiaxial low cycle fatigue data of the directionally solidified superalloy, but the maximum principal stress and the equivalent stress based on crack opening displacement could correlate the data within a small scatter. This paper proposes a new multiaxial strain parameter which takes account of the anisotropy of elastic constant of directionally solidified superalloys. The proposed strain parameter correlates the multiaxial low cycle fatigue data within a factor of two scatter band. This paper also describes the crack mode and cyclic constitutive relation of the superalloy in connection with the anisotropy of the elastic constant.

High Temperature Multiaxial Low Cycle Fatigue of CMSX-2 NI-Base Single Crystal Superalloy

1997 ◽  
Vol 119 (2) ◽  
pp. 153-160 ◽  
Author(s):  
Mitsuru Kanda ◽  
Masao Sakane ◽  
Masateru Ohnami ◽  
Tadashi Hasebe
Keyword(s):  
Single Crystal ◽  
Low Cycle Fatigue ◽  
Crack Opening ◽  
Equivalent Stress ◽  
Equivalent Strain ◽  
Fatigue Tests ◽  
Single Crystal Superalloy ◽  
Cycle Fatigue ◽  
Data Correlation ◽  
Opening Displacement

This paper describes studies of the tension-torsion multiaxial low cycle fatigue of CMSX-2 Ni-base single crystal superalloy. Tension-torsion low cycle fatigue tests were carried out at 1173K using CMSX-2 hollow cylinder specimens aligned with the {001} axis. Several multiaxial strain and stress parameters were applied to the experimental data to examine the suitability of the parameters to life prediction. All the strain parameters proposed so far gave a large scatter of the data correlation. Discrepant data correlation with the strain parameters resulted from the anisotropic stress response due to the crystallographic texture. Larger Mises equivalent stress was applied in torsion tests than in tension tests at the same Mises strain. However, Mises stress and the equivalent stress based on crack opening displacement gave a satisfactory data correlation. This study developed a new equivalent strain, taking account of the anisotropy of the elastic constants, which correlates the multiaxial low cycle fatigue data with a small scatter.

Tension-Torsion Multiaxial Low Cycle Fatigue for SUS304 and Cr-Mo-V Steels

2003 ◽  
Author(s):  
Masao Sakane ◽  
Takamoto Itoh
Keyword(s):  
Crack Opening Displacement ◽  
Low Cycle Fatigue ◽  
Crack Opening ◽  
Equivalent Stress ◽  
Equivalent Strain ◽  
304 Stainless Steel ◽  
Cycle Fatigue ◽  
Opening Displacement ◽  
Suitable Parameter ◽  
Stress Parameters

This paper describes the tension-torsion multiaxial low cycle fatigue of SUS 304 stainless steel at 923K and Cr-Mo-V steel at 823K. Combined push-pull and reversed torsion tests were carried out for the two steels. Typical multiaxial strain and stress parameters were applied to the experimental data to discriminate the suitability of the parameters. The equivalent strain based on crack opening displacement and the maximum principal strain were the most suitable parameter for the data correlation while only the equivalent stress based on crack opening displacement was most suitable as a stress parameter.

Crack opening displacement approach to assess multiaxial low cycle fatigue

2008 ◽  
Vol 30 (3) ◽  
pp. 417-425 ◽  
Author(s):  
Dimitar Tchankov ◽  
Masao Sakane ◽  
Takamoto Itoh ◽  
Naomi Hamada
Keyword(s):  
Crack Opening Displacement ◽  
Low Cycle Fatigue ◽  
Crack Opening ◽  
Cycle Fatigue ◽  
Opening Displacement ◽  
Displacement Approach

Biaxial Low Cycle Fatigue for Notched, Cracked, and Smooth Specimens at High Temperatures

1988 ◽  
Vol 110 (1) ◽  
pp. 48-54 ◽  
Author(s):  
Masao Sakane ◽  
Masateru Ohnami ◽  
Naomi Hamada
Keyword(s):  
Low Cycle Fatigue ◽  
Equivalent Stress ◽  
Torsion Test ◽  
Maximum Principal Stress ◽  
304 Stainless Steel ◽  
Cycle Fatigue ◽  
Failure Data ◽  
Biaxial Fatigue ◽  
Failure Life ◽  
Type 304

Push-pull and reversed torsion tests were carried out for notched, precracked, and smooth hollow cylindrical specimens of type 304 stainless steel at 923K in air. This paper describes the crack direction in the three types of specimens and the parameter that correlates the biaxial low cycle fatigue failure data. All types of specimens, except the smooth specimen in the reversed torsion test, failed by mode I cracking. Failure life of the specimens was discussed in connection with the crack mode. The equivalent stress based on COD could correlate the biaxial fatigue data whereas the Mises’ equivalent stress and the maximum principal stress could not.

Equi-Biaxial Tension-Compression Low Cycle Fatigue for Type 304 and Cr-Mo-V Cruciform Specimen

2003 ◽  
Author(s):  
Takamoto Itoh ◽  
Masao Sakane
Keyword(s):  
Biaxial Tension ◽  
Low Cycle Fatigue ◽  
Crack Opening ◽  
Strain Ratio ◽  
Equivalent Strain ◽  
Principal Strain ◽  
304 Stainless Steel ◽  
Cycle Fatigue ◽  
Opening Displacement ◽  
Type 304

This paper describes high temperature multiaxial low cycle fatigue lives of type 304 stainless steel and 1Cr-1Mo-1/4V steel cruciform specimens at 823K and 923K in air. Strain controlled multiaxial low cycle fatigue tests were carried out using cruciform specimens at the principal strain ratios between −1 and 1. The principal strain ratio had a significant effect on low cycle fatigue lives. Fatigue lives drastically decreased as the principal strain ratio increased. Multiaxial low cycle fatigue strain parameters were applied to the experimental data and the applicability of the parameters was discussed. The equivalent strain based on crack opening displacement (COD strain) developed in the paper and Γ*-plane parameter successfully predicted multiaxial low cycle fatigue lives. The crack morphology was also extensively discussed from not only the surface crack direction but also the crack inclination into the specimen.

High Temperature Multiaxial Low Cycle Fatigue of Cruciform Specimen

1994 ◽  
Vol 116 (1) ◽  
pp. 90-98 ◽  
Author(s):  
Takamoto Itoh ◽  
Masao Sakane ◽  
Masateru Ohnami
Keyword(s):  
High Temperature ◽  
Low Cycle Fatigue ◽  
Crack Opening ◽  
Strain Ratio ◽  
Equivalent Strain ◽  
Fatigue Tests ◽  
Principal Strain ◽  
Cycle Fatigue ◽  
Opening Displacement ◽  
Crack Morphology

This paper describes high temperature multiaxial low cycle fatigue lives of type SUS304 stainless steel and 1Cr-1Mo-1/4V steel cruciform specimens at 923K and 823K in air. Strain controlled multiaxial low cycle fatigue tests were carried out using cruciform specimens at the principal strain ratios between −1 and 1. The principal strain ratio had a significant effect on low cycle fatigue lives. Fatigue lives drastically decreased as the principal strain ratio increased. Multiaxial low cycle faitgue strain parameters were applied to the experimental data and the applicability of the parameters was discussed. The equivalent strain based on crack opening displacement (COD strain) developed in the paper and Γ* —plane parameter successfully predicted multiaxial low cycle fatigue lives. The crack morphology was also extensively discussed from not only the surface crack direction but also the crack inclination into the specimen.

Universal J-Integral to Assess Multiaxial Low Cycle Fatigue

2006 ◽  
Author(s):  
Takamoto Itoh ◽  
Masao Sakane ◽  
Dimitar Tchankov ◽  
Naomi Hamada
Keyword(s):  
Crack Opening Displacement ◽  
Low Cycle Fatigue ◽  
Crack Opening ◽  
304 Stainless Steel ◽  
Nickel Base Superalloy ◽  
Mode I ◽  
J Integral ◽  
Mode I Crack ◽  
Cycle Fatigue ◽  
Opening Displacement

This paper proposes the universal J-integral for correlating multiaxial low cycle fatigue lives, utilizing the crack opening displacement approach. The universal J-integral is a function of Young’s modulus, yield stress, strain biaxiality and specimen geometry, so that it is not necessary to conduct multiaxial low cycle fatigue tests to determine the universal J-integral. To derive the universal J-integral, J-integral for a biaxially loaded Mode I crack was equated with the equivalent strain based on crack opening displacement (COD strain). The COD strain is a parameter to express the strain intensity ahead of a Mode I crack subjected to biaxial strains, normal and parallel to the crack. The J-integral was shown to be a suitable parameter for correlating crack propagation rates in the biaxial straining conditions. The J-integral was extended to a parameter, named the universal J-integral, to correlate multiaxial low cycle fatigue lives, taking account of the material dependency. The universal J-integral successfully correlated the multiaxial low cycle fatigue lives of type 304 stainless steel, Cr-Mo-V steel, Inconel 738 LC nickel base superalloy and Sn-37Pb eutectic solder universally within a factor of three scatter band independent on the material.

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.

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