scholarly journals A strain ratio based modification on low-cycle fatigue model for asymmetric loading

Authorea ◽  
2020 ◽  
Author(s):  
Junhong Zhang ◽  
weidong li ◽  
Jiewei Lin ◽  
yongbo qiu ◽  
tianyi zhou ◽  
...  
Keyword(s):  
Low Cycle Fatigue ◽  
Strain Ratio ◽  
Cycle Fatigue ◽  
Asymmetric Loading ◽  
Fatigue Model

scholarly journals Study on the Elastic–Plastic Correlation of Low-Cycle Fatigue for Variable Asymmetric Loadings

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2451 ◽  
Author(s):  
Junhong Zhang ◽  
Weidong Li ◽  
Huwei Dai ◽  
Nuohao Liu ◽  
Jiewei Lin
Keyword(s):  
Low Cycle Fatigue ◽  
Strain Ratio ◽  
Stress Effect ◽  
Mean Stress ◽  
Cycle Fatigue ◽  
Ratcheting Strain ◽  
Asymmetric Loading ◽  
Pressure Tubing ◽  
Proposed Model ◽  
The Mean

The mean stress effect in fatigue life varies by material and loading conditions. Therefore, a classical low cycle fatigue (LCF) model based on mean stress correction shows limits in asymmetric loading cases in both accuracy and applicability. In this paper, the effect of strain ratio (R) on LCF life is analyzed and a strain ratio-based model is presented for asymmetric loading cases. Two correction factors are introduced to express correlations between strain ratio and fatigue strength coefficient and between strain ratio and fatigue ductility coefficient. Verifications are conducted through four materials under different strain ratios: high-pressure tubing steel (HPTS), 2124-T851 aluminum alloy, epoxy resin and AZ61A magnesium alloy. Compared with current widely used LCF models, the proposed model shows a better life prediction accuracy and higher potential in implementation in symmetric and asymmetric loading cases for different materials. It is also found that the strain ratio-based correction is able to consider the damage of ratcheting strain that the mean stress-based models cannot.

A modified energy-based low cycle fatigue model for eutectic solder alloy

1999 ◽  
Vol 41 (3) ◽  
pp. 289-296 ◽  
Author(s):  
X.Q Shi ◽  
H.L.J Pang ◽  
W Zhou ◽  
Z.P Wang
Keyword(s):  
Solder Alloy ◽  
Low Cycle Fatigue ◽  
Cycle Fatigue ◽  
Eutectic Solder ◽  
Fatigue Model

Low-Cycle Fatigue of a VZh175 Nickel Superalloy during Asymmetric Loading

2019 ◽  
Vol 2019 (9) ◽  
pp. 889-893
Author(s):  
M. A. Gorbovets ◽  
I. A. Khodinev ◽  
M. S. Belyaev ◽  
P. V. Ryzhkov
Keyword(s):  
Low Cycle Fatigue ◽  
Nickel Superalloy ◽  
Cycle Fatigue ◽  
Asymmetric Loading

Damage Assessment on Low Cycle Fatigue Properties of Cyclic Pre-Strained Austenitic Stainless Steel

2011 ◽  
Author(s):  
Nao Fujimura ◽  
Hiroyuki Oguma ◽  
Takashi Nakamura
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Fatigue Damage ◽  
Low Cycle Fatigue ◽  
Strain Ratio ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Damage Law ◽  
Number Of Cycles

The effects of cyclic pre-strain on low cycle fatigue properties of austenitic stainless steel were investigated, and the fatigue damage was assessed based on several parameters such as the full width at half maximum (FWHM) of diffracted X-ray profile and surface roughness of specimens. The strain-controlled tests were conducted under strain ratio Rε = −1 and various constant total strain ranges. Also the change in remnant fatigue lives were investigated when the cyclic pre-strain were applied to the specimens under the different number of cycles which were determined with reference to the usage factor UFpre ranged from 0.2 to 0.8. As a result, the remnant fatigue life of the pre-strained samples became shorter than that of the sample without pre-strain as the UFpre increased. The relationship between the pre-strain damage expressed in UFpre and the remnant fatigue damage in UFpost was roughly described by the cumulative linear damage law: UFpre + UFpost = 1. Namely, the cyclic pre-strain affected the remnant fatigue lives. In order to evaluate the effects of cyclic pre-strain on fatigue lives more precisely, the damage in the cyclic pre-straining processes was estimated by using FWHM and surface roughness. The FWHM of the specimens with pre-strain once decreased with increase in UFpre, and then increased after showing a minimum value. The surface roughness of specimens increased linearly with an increase of the number of pre-straining cycles. These results suggested that the damage due to pre-strain can be assessed by means of FWHM and surface roughness of specimens.

Fracture Modes and Low Cycle Biaxial Fatigue Life at Elevated Temperature

1987 ◽  
Vol 109 (3) ◽  
pp. 236-243 ◽  
Author(s):  
M. Sakane ◽  
M. Ohnami ◽  
M. Sawada
Keyword(s):  
Low Cycle Fatigue ◽  
Surface Oxidation ◽  
Strain Ratio ◽  
Growth Direction ◽  
Principal Strain ◽  
304 Stainless Steel ◽  
Cycle Fatigue ◽  
Biaxial Fatigue ◽  
Crack Growth Direction ◽  
Typical Strain

This paper describes the crack growth direction in biaxial low cycle fatigue under combined axial and torsional stresses in hollow cylindrical specimens of type 304 stainless steel at 923 K in air. Three types of crack are identified, namely macrocrack greater than 1 mm in length, subcracks between 0.1 mm and 1.0 mm in length, and microcracks less than 0.1 mm in length. The macrocrack direction as well as that of the subcrack depends on the principal strain ratio but the microcrack is mode I for all the principal strain ranges tested. The connection of the three types of crack is discussed in relation to the surface oxidation. Typical strain stress and criteria for the biaxial low cycle fatigue failure are applied to the experimental data and their applicability is discussed.

scholarly journals A low cycle fatigue model for low carbon manganese steel including the effect of dynamic strain aging

2016 ◽  
Vol 654 ◽  
pp. 77-84 ◽  
Author(s):  
Zhi Yong Huang ◽  
Danièle Wagner ◽  
Qing Yuan Wang ◽  
Muhammad Kashif Khan ◽  
Jean–Louis Chaboche
Keyword(s):  
Dynamic Strain Aging ◽  
Strain Aging ◽  
Low Cycle Fatigue ◽  
Manganese Steel ◽  
Dynamic Strain ◽  
Cycle Fatigue ◽  
Low Carbon ◽  
Fatigue Model

Equibiaxial Low-Cycle Fatigue Properties of Typical Pressure-Vessel Steels

1966 ◽  
Vol 88 (4) ◽  
pp. 745-754 ◽  
Author(s):  
K. D. Ives ◽  
L. F. Kooistra ◽  
J. T. Tucker
Keyword(s):  
Circular Plate ◽  
Pressure Vessel ◽  
Fatigue Testing ◽  
Low Cycle Fatigue ◽  
Strain Ratio ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Type Specimens ◽  
System A ◽  
Biaxial Fatigue

Large-size circular-plate specimens made of typical pressure-vessel materials were tested to determine their low-cycle fatigue strength. The test consisted of two distinct phases; i.e., development of an appropriate testing apparatus and the fatigue testing of the plate specimens. A unique apparatus was developed to test simply supported, circular plate-type specimens. Through a hydraulic system, a uniform pressure was applied to the specimen that resulted in a state of equibiaxial strain at the center of the plate. Tests were conducted to evaluate the pressure-deflection characteristics for various specimen strain levels. Biaxial fatigue data with a strain ratio (circumferential to radial) of 1:1 were generated for three pressure-vessel materials (A-201, A-302, T-1) for a completely reversed strain cycle. Initial cracking was used as a criterion of failure. Cracks were determined by monitoring electrical-resistance strain gages mounted on the specimen.

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