scholarly journals Influence of different loading paths on the multiaxial fatigue behavior of 2024 aluminum alloy under the same amplitude values of the second invariant of the stress deviator tensor

2020 ◽  
Vol 15 (55) ◽  
pp. 327-335
Author(s):  
Andrey Yankin ◽  
A.I. Mugatarov ◽  
V.E. Wildemann
Keyword(s):  
Experimental Data ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Test Data ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
Multiaxial Fatigue ◽  
Stress Deviator ◽  
Behavior Prediction ◽  
2024 Aluminum Alloy

2024 aluminum alloy is a common aeronautic material. During operations, construction elements made of aluminum alloys undertake complex cyclic loadings. Therefore, it is important to estimate the influence of these loadings on the durability of the material. Hereby, multiaxial fatigue tests with the same amplitude values of the second invariant of the stress deviator tensor are conducted, and test data are analyzed. The modified Sines method is utilized to predict fatigue experimental data. Results show that the model is accurate enough to fatigue behavior prediction of 2024 aluminum alloy. 

scholarly journals Multiaxial fatigue behavior of 2618 aluminum alloy

2019 ◽  
Vol 300 ◽  
pp. 09003
Author(s):  
Benaïssa Malek ◽  
Catherine Mabru ◽  
Michel Chaussumier
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Life ◽  
Internal Pressure ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
Multiaxial Fatigue ◽  
Mean Stress ◽  
Research Project ◽  
Pressure Tests

The purpose of the present research project is to study multiaxial fatigue behavior of 2618 alloy. The influence of mean stress on the fatigue behavior under tension and torsion is particularly investigated. Fatigue tests under combined tensile-torsion, in or out of phase, as well as combined tensile-torsion-internal pressure tests have also been conducted. Multiaxial fatigue results are analyzed according to Fatemi-Socie criterion to predict the fatigue life.

scholarly journals Fatigue Behavior of Conventional and Stationary Shoulder Friction Stir Welded EN AW-5754 Aluminum Alloy Using Load Increase Method

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1510
Author(s):  
Abootorab Baqerzadeh Chehreh ◽  
Michael Grätzel ◽  
Jean Pierre Bergmann ◽  
Frank Walther
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Strength ◽  
Aluminum Alloys ◽  
Efficient Method ◽  
Fatigue Behavior ◽  
Friction Stir ◽  
Stationary Shoulder ◽  
Aluminum Sheets ◽  
Load Increase ◽  
Weld Seams

The load increase method, which is highly efficient in rapidly identifying the fatigue performance and strength of materials, is used in this study to investigate friction stir welded (FSW) EN AW-5754 aluminum alloys. Previous investigations have demonstrated the accuracy and efficiency of this method compared to Woehler tests. In this study, it is shown that the load increase method is a valid, accurate and efficient method for describing the fatigue behavior of FSW weld seams. The specimen tests were performed on 2 mm thick aluminum sheets using conventional and stationary tool configurations. It is shown that an increase in fatigue strength of the FSW EN AW-5754 aluminum alloys can be achieved by using the stationary shoulder tool configuration rather than the conventional one.

Multiaxial Fatigue of 6061-T6 Aluminum Alloy under Corrosive Environment

2016 ◽  
Vol 853 ◽  
pp. 77-82
Author(s):  
Xu Chen ◽  
Rui Si Xing ◽  
Xiao Peng Liu
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Life ◽  
Stress Amplitude ◽  
Low Cycle Fatigue ◽  
Cyclic Hardening ◽  
Cyclic Softening ◽  
Fatigue Tests ◽  
Plastic Strain Amplitude ◽  
Multiaxial Fatigue ◽  
Corrosive Environment

Aluminium alloys are widely used in the fields of automobile, machinery and naval construction. To investigate the effect of non-proportional loadings and corrosive environment on the fatigue resistance of 6061-T6 aluminum alloy, a set of uniaxial and multiaxial low cycle fatigue tests were carried out. Firstly, the results of uniaxial tests showed that the alloy exhibited cyclic hardening then cyclic softening. With the increase of stress amplitude the cyclic softening became pronounced. The increasing of plastic deformation was basically cyclically stable with small plastic strain amplitude accumulation when the stress amplitude was lower than 200MPa ,while it was increasing rapidly when the stress amplitude was higher than 220MPa. Secondly, it was observed that non-proportional cycle additional hardening of 6061-T6 aluminum alloy was little. While the fatigue life was badly affected by the loading paths. Thirdly ,the fatigue corrosion interactions were also talked about in details by performing the tests under the same loading conditions with corrosive environment. The experiment proved that the seawater corrosion has huge impact on fatigue life under pH 3. Finally, a multi-axial fatigue life prediction model was used to predict the fatigue life with or without the corrosive environment which showed a good agreement with experimental data.

Effects of Ultrasonic Deep Rolling on Fatigue Performance of Pre-Corroded 7A52 Aluminum Alloy

2011 ◽  
Vol 189-193 ◽  
pp. 897-900 ◽  
Author(s):  
Xiong Lin Ye ◽  
You Li Zhu ◽  
Dong Hu Zhang
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Life ◽  
Aluminum Alloys ◽  
Residual Stresses ◽  
Fatigue Behavior ◽  
Fatigue Performance ◽  
Deep Rolling ◽  
Fatigue Crack Nucleation ◽  
7A52 Aluminum Alloy ◽  
Compressive Residual Stresses

The effects of ultrasonic deep rolling (UDR) on the fatigue behavior of pre-corroded 7A52 aluminum alloys were investigated. By means of X-Ray diffraction stress measurements and scanning electron microscopy (SEM), residual stress and fractograph of 7A52 aluminum alloys with and without UDR treatment were analyzed. The results indicated that the UDR produced compressive residual stresses with depth approaching 1mm. UDR treatment can extend the fatigue life of the pre-corroded 7A52 specimens to a large extent, depending on the level of corrosion and UDR parameter. For the slightly corrode specimens, the UDR treatment changed the fatigue crack nucleation site from surface to the transition zone between the compressive residual stresses and tensile stresses, resulted in a much longer fatigue life. For the severely corrode specimens, the crack still nucleated by intergranular cracking, however, due to the compressive residual stresses introduced and the closure of the corrosion pits and corrosion micro-crocks, UDR treatment still improved fatigue performance of the pre-corroded 7A52 aluminum alloy substantially.

scholarly journals Multiaxial Fatigue Behavior of High-Density Polyethylene (HDPE) Including Notch Effect: Experiments and Modeling

2019 ◽  
Vol 300 ◽  
pp. 05001 ◽  
Author(s):  
Mohammadreza Amjadi ◽  
Ali Fatemi
Keyword(s):  
High Density Polyethylene ◽  
Fatigue Behavior ◽  
Equivalent Stress ◽  
Fatigue Tests ◽  
Multiaxial Fatigue ◽  
High Density ◽  
Analytical Models ◽  
Axial Torsion ◽  
Stress Concentration Effect ◽  
Von Mises

High-Density Polyethylene (HDPE) is used in many industries with many applications from automotive industry to biomedical implants. It can be manufactured using different processing techniques including compression molding, injection molding, and blow molding. Multiaxial loading and non-proportionality between different loading sources are inevitable in many applications. It is shown that the common multiaxial fatigue criteria such as von Mises equivalent stress are not able to correlate the multiaxial fatigue data. In this study, multiaxial fatigue behavior of neat HDPE is investigated using hollow tubular specimens through experimental fatigue tests. Axial, torsion, and combined in phase and out-of-phase axial-torsion fatigue tests were conducted. Stress concentration effect on multiaxial fatigue behavior was also studied. Experimental results and analytical models used to account for the aforementioned effects are presented and discussed in this paper.

Multiaxial fatigue life estimation of defective aluminum alloy considering the microstructural heterogeneities effect

2018 ◽  
Vol 233 (9) ◽  
pp. 1830-1842
Author(s):  
Amal Ben Ahmed ◽  
Ahmad Bahloul ◽  
Mohamed Iben Houria ◽  
Anouar Nasr ◽  
Raouf Fathallah
Keyword(s):  
Aluminum Alloy ◽  
High Cycle Fatigue ◽  
Fatigue Behavior ◽  
Multiaxial Fatigue ◽  
Cycle Fatigue ◽  
Post Heat Treatment ◽  
Stressed Volume ◽  
Good Ability ◽  
Fatigue Life Estimation ◽  
Chaboche Model

The Al–Si–Mg high-cycle fatigue behavior is mainly affected by the microstructural heterogeneities and the presence of casting defects. This attempt aims to develop an analytical approach based on the evaluation of the highly stressed volume caused by local porosities and defined as the affected area methodology. The proposed approach is able to predict the aluminum alloy fatigue response by considering the effect of microstructure described by the secondary dendrite arm spacing and its correlation with the defect size effect. A representative elementary volume model is implemented to evaluate the stress distribution in the vicinity of the defect and to determine its impact on the high-cycle fatigue resistance. Work hardening due to cyclic loading is considered by applying the Lemaitre–Chaboche model. The Kitagawa–Takahashi diagrams corresponding to different microstructures and for two loading ratios: R σ = 0 and R σ = −1 were simulated based on the AA method. Simulations were compared to the experimental results carried out on cast aluminium alloy A356 with T6 post heat-treatment. The results show clearly that the proposed approach provides a good estimation of the A356-T6 fatigue limit and exhibits good ability in simulating the Kitagawa–Takahashi diagrams for fine and coarse microstructures.

Effects of chromic acid anodizing on fatigue behavior of 7050 T7451 aluminum alloy

2021 ◽  
Vol 63 (9) ◽  
pp. 805-810
Author(s):  
Çağrı İlhan ◽  
Rıza Gürbüz
Keyword(s):  
Aluminum Alloy ◽  
Stress Ratio ◽  
Chromic Acid ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
Constant Amplitude ◽  
Aluminum Oxide Layer ◽  
Fatigue Life Reduction ◽  
Selection Of ◽  
Scanning Electron

Abstract The effect of chromic acid anodizing (CAA) surface treatment on 7050 T7451 aluminum alloy was presented in this study in terms of fatigue behavior. CAA is a treatment against corrosion by producing aluminum oxide layer (Al2O3) at the surface. However, fatigue performance of 7050 T7451 is affected by the coating. In this study, eight different CAA processes were examined with regard to etching stage of pre-treatments by using an alkaline etchant and/or acid etchants with various immersion times. Optical microscopic examinations were applied in order to determine pitting characteristics for the selection of CAA process parameters before fatigue tests. A CAA process was selected among eight processes in terms of pitting characteristics in order to apply fatigue specimens. Four fatigue test groups were determined to investigate bare condition of 7050 T7451 and sub-stages of the CAA particularly. Constant amplitude axial fatigue tests were conducted on specimens at 91 Hz at stress ratio (R) -1 until run-out criteria, which was 106 cycles. Fatigue life reduction was determined due to pretreatments of CAA. Fracture surfaces of the specimens were examined by scanning electron microscope (SEM) to investigate morphology and crack initiation sites.

Low Cycle and Multiaxial Fatigue Behavior of Three Al-Mg-Si Alloys

2014 ◽  
Vol 891-892 ◽  
pp. 1335-1340
Author(s):  
Denise F. Laurito-Nascimento ◽  
Ana Márcia Barbosa da Silva Antunes ◽  
Carlos Antonio Reis Pereira Baptista ◽  
José Célio Dias ◽  
Angelo Souza
Keyword(s):  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Fatigue Behaviour ◽  
Fatigue Tests ◽  
Multiaxial Fatigue ◽  
Damping Capacity ◽  
Reliability Engineering ◽  
Principal Stresses ◽  
Engineering Structures ◽  
6Xxx Series

Al-Mg-Si alloys (6xxx series) are medium strength structural alloys, with good corrosion resistance, good weldability and high damping capacity. They represent a high volumetric fraction of extruded aluminium alloys which are produced for commercial use and have been increasingly applied in the automotive industry. For structural materials, the fatigue strength is the most important factor to ensure a long-term reliability. Engineering structures such as aircrafts and automobiles usually undergo complex multiaxial loadings, which lead to changes of the principal stresses and strains directions in components during a loading cycle. In this study, fatigue tests were performed in three Al-Mg-Si alloys, namely AA 6005, AA 6351 and AA 6063, tempered and aged for the T6 condition. A comparative study was undertaken by assessing their Low Cycle Fatigue (LCF) properties and multiaxial fatigue behaviour using round smooth specimens. Strain-controlled fully reversed axial loadings and distinct combinations of axial-torsional fully reversed stress cycles, including in-phase and 90o out-of-phase loadings were adopted for the tests. The collected data are discussed in relation to some well-known multiaxial fatigue models.

The Study on Fatigue Behavior in Very High Cycle of 5083 Aluminum Alloy

2014 ◽  
Vol 626 ◽  
pp. 359-364
Author(s):  
Gui Ling Yan ◽  
Hong Wang ◽  
Guo Zheng Kang ◽  
Zhou Chen
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
Uniaxial Loading ◽  
Source Zone ◽  
Bending Fatigue ◽  
Almost All ◽  
Bending Loading ◽  
5083 Aluminum Alloy ◽  
Very High

Fatigue tests were carried out at frequent of 20 kHz for 5083 aluminum alloy. The loading way is uniaxial and bending loading. The S-N curve of uniaxial loading presents a duplex curve corresponding to surface fracture and interior fracture. However the S-N curve of the bending fatigue shows the continuous curve. This demonstrates that different loading ways lead to different S-N curve characteristics. For uniaxial loading, almost all crack initiated interior of specimen in the very high cycle regime. The crack source zone appears wear away because of the constant pressure and grinding of this area in the process of cyclic loading. For the symmetric bending loading, the crack of corner in the specimen expands at different rates and direction.

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