Biaxial Tension-Tension Fatigue Strengths of Metals

1949 ◽  
Vol 16 (4) ◽  
pp. 383-388
Author(s):  
Joseph Marin
Keyword(s):  
Fatigue Strength ◽  
Axial Load ◽  
Fatigue Testing ◽  
Biaxial Tension ◽  
Testing Machine ◽  
Tubular Specimen ◽  
Principal Stresses ◽  
Biaxial Fatigue ◽  
Thin Walled ◽  
Stress Ratios

Abstract This paper describes a new fatigue testing machine for the application of tension-tension biaxial stresses and presents the results of an investigation on the biaxial fatigue strength of Alcoa 24S-T. The influence of various ratios of the maximum values of the principal stresses upon the fatigue strength was determined. Fluctuating biaxial tensile stresses were produced by subjecting a thin-walled tubular specimen to a pulsating internal pressure and a pulsating axial load. The maximum and minimum values of the principal stresses were kept in phase. Fatigue strengths and S-N diagrams for four principal stress ratios were obtained.

The Relationship Between Tensile and Fatigue Strength of Friction Welded Steel Joints

2015 ◽  
Author(s):  
S. T. Selvamani ◽  
K. Palanikumar ◽  
K. Shanmugam ◽  
S. Divagar ◽  
M. Vigneshwar
Keyword(s):  
Fatigue Strength ◽  
Fatigue Testing ◽  
High Carbon Steel ◽  
Testing Machine ◽  
Fatigue Properties ◽  
Uniaxial Tensile ◽  
Sensitivity Factor ◽  
Welded Steel ◽  
Steel Joints ◽  
The Relationship

The friction welding of AISI 52100 grade low chromium and high carbon steel joints are investigated in this work to evaluate the fatigue life of the joints by conducting the experiments using servo hydraulic fatigue testing machine at different stress levels. All the experiments are conducted under uniaxial tensile loading condition (stress ratio=0). Fatigue strength, fatigue notch factor (Kf) and notch sensitivity factor (q) are evaluated for the optimized joints and the relationship between tensile and fatigue properties of Fully Deformed None (FDZ) is established. Finally, the Characteristics of friction welded joint is investigated with the help of Scanning Electron Microscope and Optical Microscopy under optimized condition.

Fatigue Behaviour of Friction Stir Welded AZ31B Magnesium Alloy Joints

2015 ◽  
Vol 787 ◽  
pp. 355-360
Author(s):  
S. Venkatesan ◽  
G.P. Rajamani ◽  
V. Balasubramanian ◽  
G. Padmanaban
Keyword(s):  
Fatigue Strength ◽  
Fatigue Testing ◽  
Corrosion Behaviour ◽  
Testing Machine ◽  
Fatigue Behaviour ◽  
Fusion Welding ◽  
Sensitivity Factor ◽  
Metal Fatigue ◽  
Friction Stir ◽  
Fatigue Notch Factor

Friction stir welding (FSW) is a relatively better joining technique particularly for magnesium and aluminum alloys that are difficult to weld by fusion welding techniques. Fusion welding of these alloys is not preferable due to hot cracking, formation of porosity, etc. However solid state welding techniques, such as, friction sitr welding are found to offer solution to the above problems. Many research papers available in open literature focusing tensile properties, microstructural characteristics, and corrosion behaviour of friction stir welded AZ31B magnesium alloys but fatigue behaviour of these welds are not yet investigated. Hence, in this investigation, an attempt has been made to evaluate fatigue behaviour of friction stir welded rolled plates of AZ31B magnesium alloys.Fatigue experiment was conducted using servo hydraulic controlled fatigue testing machine. Fatigue strength, fatigue notch factor and notch sensitivity factor were evaluated. It is found that the fatigue strength of AZ31B welded joints is 46 MPa at 2x106cycles which is approximately 34 % lower than that of the base metal fatigue strength.

Combined Stress Tests in Plasticity

1956 ◽  
Vol 23 (1) ◽  
pp. 43-48
Author(s):  
Aris Phillips ◽  
Lloyd Kaechele
Keyword(s):  
Uniaxial Tension ◽  
Plastic Region ◽  
Uniaxial Stress ◽  
Stress Tests ◽  
Combined Stress ◽  
Principal Stresses ◽  
Thin Walled ◽  
Stress Ratios

Abstract A substantial number of combined stress tests on thin-walled tubes of aluminum 2S-O are reported. In most of the tests the tubes have been subjected to combined tension and torsion with variable stress ratios. In the last six tests each tube has first been subjected to uniaxial tension until sufficiently deep in the plastic region and then this state of uniaxial stress has been rotated while the magnitude of the principal stresses remained constant. The purpose of the tests was to get information as to the validity of the incremental theories of plasticity. The results of these tests favor the incremental theories.

DEVELOPMENT OF AN AXIAL - TORSION BIAXIAL FATIGUE TESTING MACHINE

2015 ◽  
Author(s):  
Eleazar Cristian Mejia Sanchez ◽  
Marco Antonio Meggiolaro ◽  
Jaime Tupiassú Pinho de Castro
Keyword(s):  
Fatigue Testing ◽  
Testing Machine ◽  
Axial Torsion ◽  
Biaxial Fatigue

Fatigue Strength Evaluation of Defects Embedded in Large-Sized Stud Bolt of Marine Engine

2005 ◽  
Author(s):  
Kukbin Kim ◽  
Byung-Joo Kim ◽  
Jinsoo Park ◽  
Young-Cheol Yoon ◽  
Deukjin Park
Keyword(s):  
Fatigue Strength ◽  
Fatigue Testing ◽  
Propagation Rate ◽  
Initiation Site ◽  
Defect Size ◽  
Strength Evaluation ◽  
Small Defect ◽  
Stress States ◽  
Stress Ratios ◽  
Beach Marks

Millimeter-sized defects are often found during inspection near the centerline of the shank of large-sized stud bolts. Determination of allowable defect size is practically required in view of safety. An experimental investigation on the fatigue strength of the stud bolt has been carried out in order to evaluate the effect of defects embedded in the stud bolt on the fatigue strength. Fatigue testing was conducted for stress ratios of 0.0, 0.4 and 0.7 using plain specimens and defected specimens having a defect embedded inside to examine the fatigue limit according to the stress ratio. Macroscopic and microscopic analyses were also conducted in order to determine initial defect size, crack initiation site and propagation rate from beach marks on the fracture surface. Existing small defect evaluation methods currently available were used for the strength evaluation. Allowable internal defect size was determined based on the high mean and high cycle stress states of the bolt by linear elastic fracture mechanics.

Fatigue Strength of Ion Nitrided Tool Steel

2006 ◽  
Vol 324-325 ◽  
pp. 475-478
Author(s):  
Mian Zhang ◽  
Shinichi Nishida ◽  
Nobusuke Hattori
Keyword(s):  
Fatigue Strength ◽  
Fatigue Test ◽  
Tool Steel ◽  
Surface Composition ◽  
Fatigue Testing ◽  
Testing Machine ◽  
Surface Hardness ◽  
Fatigue Properties ◽  
Ion Nitriding ◽  
Rotating Bending Fatigue

The authors have studied and clarified that ion nitriding was able to improve the fatigue properties of tool steel. Five kinds of ion nitriding methods (ion nitriding condition is different) were used in this study. The fatigue test had been performed using a rotating bending fatigue testing machine to investigate the effects of ion nitriding on fatigue properties of tool steel. The fractography was analyzed using a scanning electron microscope (SEM), and hardness distribution was also investigated using a microhardness tester. As a result, the fatigue strength and hardness of the ion nitrided specimen increased after ion nitriding processing. It is considered that the compressive residual stress which produced by ion nitriding processing in the layer reduced fatigue fracture, and the altered surface composition improved surface hardness. According to the results of the fatigue test, the optimal ion nitriding method on improving the fatigue limit of tool steel was determined. The hardness of the specimens remarkably increased after ion nitriding processing.

Fatigue Strength of Ductile Iron in Ultra-High Cycle Regime

2014 ◽  
Vol 874 ◽  
pp. 43-48 ◽  
Author(s):  
Robert Ulewicz ◽  
František Nový ◽  
Jacek Selejdak
Keyword(s):  
Cast Iron ◽  
Fatigue Strength ◽  
Ductile Iron ◽  
High Frequency ◽  
Fatigue Testing ◽  
Testing Machine ◽  
Fatigue Tests ◽  
Essential Factor ◽  
Equipment Safety ◽  
Sn Curve

Machine and equipment safety is the most essential factor that determines the choice of a particular material used in the construction phase. Failure analyses in engineering praxis demonstrate that nearly 90 % of all cases of failures are caused by fatigue. For popular technical applications such as cars and trains, the durability expected for some components ranges from 108to 1010loading cycles. However, only few studies have been carried out for more than 107cycles. The SN curve in the ultra-wide life region must be determined in order to ensure actual fatigue strength and safety of these components. This paper presents the results obtained from fatigue tests carried out by means of a high-frequency fatigue testing machine for the three grades of ductile iron: with ferritic-pearlitic matrix (GGG50), with pearlitic-ferritic matrix (GGG60) and ADI cast iron in the range from 106up to 1010cycles.

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