On the Use of Low and High Cycle Fatigue Damage Models

2013 ◽  
Vol 569-570 ◽  
pp. 1029-1035
Author(s):  
Magd Abdel Wahab ◽  
Irfan Hilmy ◽  
Reza Hojjati-Talemi
Keyword(s):  
Crack Initiation ◽  
Fatigue Damage ◽  
Damage Evolution ◽  
High Cycle Fatigue ◽  
Low Cycle Fatigue ◽  
Damage Model ◽  
Fretting Fatigue ◽  
Cycle Fatigue ◽  
Evolution Law ◽  
Number Of Cycles

In this paper, Continuum Damage Mechanics (CDM) theory is applied to low cycle and high cycle fatigue problems. Damage evolution laws are derived from thermodynamic principles and the fatigue number of cycles to crack initiation is expressed in terms of the range of applied stresses, triaxiality function and material constants termed as damage parameters. Low cycle fatigue damage evolution law is applied to adhesively bonded single lap joint. Damage parameters as function of stress are extracted from the fatigue tests and the damage model. High cycle fatigue damage model is applied to fretting fatigue test specimens and is integrated within a Finite Element Analysis (FEA) code in order to predict the number of cycles to crack initiation. Fretting fatigue problems involve two types of analyses; namely contact mechanics and damage/fracture mechanics. The high cycle fatigue damage evolution law takes into account the effect of different parameters such as contact geometry, axial stress, normal load and tangential load.

Analysis on High Cycle Fatigue Properties and Fatigue Damage Evolution of TC25 Titanium Alloy

2016 ◽  
Vol 697 ◽  
pp. 658-663
Author(s):  
Rong Guo Zhao ◽  
Ya Feng Liu ◽  
Yong Zhou Jiang ◽  
Xi Yan Luo ◽  
Qi Bang Li ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Fatigue Life ◽  
Strain Hardening ◽  
Fatigue Damage ◽  
Damage Evolution ◽  
High Cycle Fatigue ◽  
Damage Model ◽  
Fatigue Properties ◽  
Test Machine ◽  
Cycle Fatigue

The high cycle fatigue tests for smooth specimens of TC25 titanium alloy under different stress ratios are carried out on a MTS 809 Material Test Machine at a given maximum stress level of 917MPa at ambient temperature, the high cycle fatigue lifetimes for such alloy are measured, and the effects of stress amplitude and mean stress on high cycle fatigue life are analyzed. The initial resistance is measured at the two ends of smooth specimen of TC25 titanium alloy, every a certain cycles, the fatigue test is interrupted, and the current resistance values at various fatigue cycles are measured. The ratio of resistance change is adopted to characterize the fatigue damage evolution in TC25 titanium alloy, and a modified Chaboche damage model is applied to derive the fatigue damage evolution equation. The results show that the theoretical calculated values agree well with the test data, which indicates that the modified Chaboche damage model can precisely describe the accumulated damage in TC25 titanium alloy at high cycle fatigue under unaxial loading. Finally, the high cycle fatigue lifetimes for TC25 titanium alloy specimens at different strain hardening rates are tested at a given stress ratio of 0.1, the effect of strain hardening on fatigue life is investigated based on a microstructure analysis on TC25 titanium alloy, and an expression between fatigue life and strain hardening rate is derived

A Multi-Level Low Cycle Fatigue Damage Model for Forging Die Material

2006 ◽  
Vol 514-516 ◽  
pp. 804-809
Author(s):  
S. Gao ◽  
Ewald Werner
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Low Cycle Fatigue ◽  
Damage Model ◽  
Fatigue Loading ◽  
Cycle Fatigue ◽  
Die Material ◽  
Multi Level ◽  
Loading Sequence ◽  
Forging Die

The forging die material, a high strength steel designated W513 is considered in this paper. A fatigue damage model, based on thermodynamics and continuum damage mechanics, is constructed in which both the previous damage and the loading sequence are considered. The unknown material parameters in the model are identified from low cycle fatigue tests. Damage evolution under multi-level fatigue loading is investigated. The results show that the fatigue life is closely related to the loading sequence. The fatigue life of the materials with low fatigue loading first followed by high fatigue loading is longer than that for the reversed loading sequence.

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.

scholarly journals Extremely-Low-Cycle Fatigue Damage for Beam-to-Column Welded Joints Using Structural Details

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1768
Author(s):  
Lizhen Huang ◽  
Weilian Qu ◽  
Ernian Zhao
Keyword(s):  
Fatigue Damage ◽  
Welded Joints ◽  
Low Cycle Fatigue ◽  
Damage Model ◽  
Multiaxial Fatigue ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Butt Weld ◽  
Damage Models ◽  
Structural Details

The multiaxial fatigue critical plane method can be used to evaluate the extremely-low-cycle fatigue (ELCF) damage of beam-to-column welded joints in steel frameworks subjected to strong seismic activity. In this paper, fatigue damage models using structural detail parameters are studied. Firstly, the fatigue properties obtained from experiments are adopted to assess ELCF life for steel frameworks. In these experiments, two types of welded specimens, namely, plate butt weld (PB) and cruciform load-carrying groove weld (CLG), are designed according to the structural details of steel beam and box column joints, in which both structural details and welded factors are taken into account. Secondly, experiments are performed on three full-scale steel welded beam-to-column joints to determine the contribution of stress and/or strain to damage parameters. Finally, we introduce a modification of the most popular fatigue damage model of Fatemi and Socie (FS), modified by us in a previous study, for damage evaluation, and compare this with Shang and Wang (SW) in order to examine the applicability of the fatigue properties of PB and CLG. This study shows that the modified FS model using the fatigue properties of CLG can predict the crack initiation life and evaluate the damage of beam-to-column welded joints, and can be subsequently used for further investigation of the damage evolution law.

A Perspective on Fatigue Damage by Decoupling LCF and HCF Loads in a Type 316LN Stainless Steel

2015 ◽  
Vol 34 (5) ◽  
Author(s):  
Aritra Sarkar ◽  
A. Nagesha ◽  
R. Sandhya ◽  
M.D. Mathew
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Fatigue Damage ◽  
Strain Amplitude ◽  
High Cycle Fatigue ◽  
Low Cycle Fatigue ◽  
Applied Strain ◽  
Cycle Fatigue ◽  
316Ln Stainless Steel ◽  
Type 316Ln Stainless Steel

AbstractPrior low cycle fatigue (LCF) deformation in a 316LN austenitic stainless steel reduced the remnant high cycle fatigue (HCF) life as a function of the amount of LCF exposure and the applied strain amplitude. A critical LCF pre-damage was found necessary for an effective LCF-HCF interaction to take place.

Numerical Simulation Study on High-Cycle Fatigue Damage for Metals

2014 ◽  
Vol 941-944 ◽  
pp. 1477-1482
Author(s):  
Xu Tao Nie ◽  
Wan Hua Chen ◽  
Yuan Xing Wang
Keyword(s):  
Numerical Simulation ◽  
Fatigue Damage ◽  
High Cycle Fatigue ◽  
Solid Mechanics ◽  
Damage Model ◽  
Simulation Method ◽  
Research Field ◽  
Cycle Fatigue ◽  
Thermodynamic Potentials ◽  
Fatigue Damage Analysis

High-cycle fatigue damage analysis and life prediction is a most crucial problem in the research field of solid mechanics. Based on the thermodynamic potentials in the framework of thermodynamics a numerical method for high-cycle fatigue damage was studied and provided by using a two-scale damage model. Furthermore, according to the “jump-in-cycles” procedure the numerical simulation of high-cycle fatigue damage was implemented in a user subroutine of ABAQUS software. Finally, a numerical simulation instance of high-cycle fatigue damage was provided and compared with a set of test data, which indicates that the numerical simulation method presented is reasonable and applicable.

High Cycle Fatigue Behavior of Cold Forging Die Steel

2009 ◽  
Vol 417-418 ◽  
pp. 225-228 ◽  
Author(s):  
Ryuichiro Ebara ◽  
R. Nohara ◽  
Rintaro Ueji ◽  
A. Ogura ◽  
Y. Ishihara ◽  
...  
Keyword(s):  
Crack Initiation ◽  
High Cycle Fatigue ◽  
Fatigue Behavior ◽  
Cold Forging ◽  
Propagation Mode ◽  
Cycle Fatigue ◽  
Die Steel ◽  
Initiation And Propagation ◽  
Number Of Cycles ◽  
Forging Die

High cycle fatigue behavior of the representative cold forging die steel, YXR3 with Rockwell C scale hardness number of 60.0 is investigated. Axial fatigue strength of plane and notched bar specimens with stress concentration factor, Kt of 1.5, 2.0 and 2.5 is presented. The emphasis is placed upon the subsurface crack initiation observed on notched specimens failed at number of cycles over than 106 cycles. Crack initiation and propagation mode of cold forging die steel is discussed with respect to fracture surface morphology.

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