scholarly journals USING THE LINEAR DAMAGE SUMMATION HYPOTHESIS IN THE FATIGUE TESTS ANALYSIS OF TITANIUM ALLOY PIECES

2021 ◽  
pp. 1-6
Author(s):  
Evgeniya Gnatyuk ◽  
Arkadiy Skvortsov ◽  
Svetlana Kuleshova
Keyword(s):  
Titanium Alloy ◽  
Endurance Limit ◽  
Linear Regression Analysis ◽  
High Strength ◽  
Fatigue Tests ◽  
Test Pieces ◽  
Operational Testing ◽  
Strength Material ◽  
Number Of Cycles ◽  
Damage Summation

This paper presents the results of fatigue tests of titanium alloy, and also describes the use of the hypothesis of linear damage summation when processing the results of fatigue tests. On the basis of the experiments, the endurance limit of the titanium alloy was determined, which lies in the range from 460 to 480 MPa with the number of cycles from 105 to 108. The purpose of the experiment was to determine the endurance limit of high strength material, as well as a mathematical measurement of the expected destruction. In this study, empirical methods were used such as indirect observation of the object under study, description and measurement of technical influences exerted on it by an artificial means, as well as linear regression analysis to establish the relationship between stress and durability. As a result of the experiment, fatigue curves were obtained for various probabilities, which give grounds to conclude that the use of the linear damage summation hypothesis in processing the results of fatigue tests entails a satisfactory practical accuracy of the calculation of endurance limit. This experiment is aimed at improving metal production by studying the quality of titanium alloy test pieces and performing mathematical analysis of possible problems arising in the process of its operational testing.

scholarly journals Influence of Crystal Structure of Nitride Compound Layer on Torsion Fatigue Strength of Alloy Steel

Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1352 ◽  
Author(s):  
Yoshitomi Yamada ◽  
Eto Hirohito ◽  
Koji Takahashi
Keyword(s):  
Crystal Structure ◽  
Fatigue Strength ◽  
Crystal Structures ◽  
Alloy Steel ◽  
High Strength ◽  
Compound Layer ◽  
Fatigue Tests ◽  
Commercial Vehicles ◽  
Torsional Fatigue ◽  
Number Of Cycles

The demand for high-strength components for commercial vehicles has recently increased. Conventional gas nitrocarburizing has been used to increase strength and productivity of the crankshaft. A potential-controlled nitriding process was recently developed to control the crystal structure of the nitride compound layer. It has been found that this treatment improves the bending fatigue strength compared with conventional treatment, and has the potential to cope with the increase in crankshaft strength. However, the effect of torsional fatigue strength has not been studied. Therefore, in this study, the influence of the crystal structure of the nitride compound layer on torsional fatigue strength was investigated. Two kinds of test specimens with different crystal structures of the compound layer were prepared using gas nitriding treatment with controlled nitriding potential for an alloy steel bar (JIS-SCM435). Torsional fatigue tests were carried out using these test specimens. Although the compound layer of these test specimens had different crystal structures, the hardness distribution and residual stress distribution on the diffusion layer were almost the same. The relationship between stress amplitude and number of cycles to failure (S-N curve) showed that the torsional fatigue limits of the specimens were almost the same. This indicates that the crystal structure of the nitride compound layer did not affect the torsional fatigue limits, because the origin of the torsional fatigue failure is inside the specimen.

Effect of the chassis parts surface condition from high-strength titanium alloy VT-22 in the process of fatigue tests

2021 ◽  
Vol 2021 (2) ◽  
pp. 45-53
Author(s):  
A. O. Gorpenko ◽  
◽  
O.I. Semenets ◽  
O. M. Doniy ◽  
K.O. Valuiska ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Surface Defects ◽  
Surface Condition ◽  
High Strength ◽  
Surface Damage ◽  
Cylindrical Part ◽  
Fatigue Tests ◽  
Landing Gear ◽  
Premature Failure ◽  
Surface Machining

The research focuses on the influence of the surface condition on the resource of high-strength titanium alloy VT-22 landing gear details during fatigue tests. The tests were performed on special facilities that simulate the workload on a rod detail at the stage of extending and retraction of the landing gear. Fatigue tests were performed on four rods. Rods № 1-3 were destroyed at the lugs level, rod №4 withstood the entire cycle of loads, and was examined in an undamaged state. It was found that the cause of the failure of the rod №1 was axial play formation as a result of bracket lug deformation, which led to shock loads on the lug of the rod №1 during the tests. The destruction of the rod №2 could be caused by the shock axial loads due to changes in the characteristics and load values of the facility on the rod №2. The priority factor influencing the premature failure of the rod №3 was the high risks from surface machining in the most loaded part of the rod №3, namely at the R-junction of the cylindrical part to the lug. The presence of surface defects formed during the manufacturing stage, as well as the presence of deep scratches in the area with high load reduce the life of rod № 3 fivefold compared to the undamaged rod № 4, which had no visible surface defects. Surface damage detected in the non-chromized area of the rods can be eliminated by blasting with subsequent surface polishing, which will provide the required resource of the detail (rod № 4). Keywords: high-strength titanium alloy VT-22, rod, fatigue tests, surface defects, structure of the surface layer.

The generalized regularities of damageability and integrity in estimations of the endurance in conditions of variability of loading regimes

2019 ◽  
Vol 85 (9) ◽  
pp. 61-65
Author(s):  
N. A. Makhutov
Keyword(s):  
Life Time ◽  
Cyclic Strength ◽  
Laboratory Diagnostics ◽  
Methodological Issues ◽  
Break Points ◽  
Number Of Cycles ◽  
Cyclic Damage ◽  
Damage Summation ◽  
Temperature Factors

We consider and analyze general methodological issues regarding the strength and endurance (life-time) of the materials and structure elements under a combined effect of various force, deformation and temperature factors. The Journal "Zavodskaya laboratoriya. Diagnostika materialov" (Industrial laboratory. Diagnostics of materials) has launched systematic publications on this problematic since 2018. For many decades, domestic and foreign laboratory studies have gleaned to a traditional methodology for obtaining initial curves of the long-term and cyclic strength that related the breaking stresses with time or number of cycles. These curves, with the characteristic sections and break points, separating the areas of elastic and inelastic (plastic strain or creep strain) strain, are used in analysis of long-term and cyclic damage. Using the elementary linear law of damage summation, it is possible to calculate at a first approximation the strength and endurance under varying conditions of loading. Stepping up the requirements to the accuracy of calculations necessitates a transition from force fracture criteria (at stresses a) to deformation criteria (in elastic and inelastic deformations e). Thus, it becomes possible to construct and use a unified expression for the curve of the long-term cyclic fracture (taking into account the temporal x and cyclic N factors) and a long-term cyclic damage. With such approach it is possible to remain the linear law of damage summation though those damages are obviously nonlinear. The goal of the study is to continue and support the discussion of the most complex problems of a comprehensive assessment of the strength, resource, survivability and safety of high-risk engineering equipment within the journal pages.

ALCOA 2024

Alloy Digest ◽  
1998 ◽  
Vol 47 (3) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Surface Treatment ◽  
Tensile Properties ◽  
Surface Finish ◽  
High Strength ◽  
Machined Surface ◽  
2024 Alloy ◽  
Structural Applications ◽  
Strength Material

Abstract Alcoa 2024 alloy has good machinability and machined surface finish capability, and is a high-strength material of adequate workability. It has largely superseded alloy 2017 (see Alloy Digest Al-58, August 1974) for structural applications. The alloy has comparable strength to some mild steels. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on corrosion resistance as well as machining and surface treatment. Filing Code: AL-346. Producer or source: ALCOA Wire, Rod & Bar Division.

MEEHANITE GB300

Alloy Digest ◽  
2020 ◽  
Vol 69 (11) ◽  
Keyword(s):  
Thermal Conductivity ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Gray Cast Iron ◽  
High Strength ◽  
Heat Treating ◽  
Spheroidal Graphite ◽  
Cast Irons ◽  
Test Pieces ◽  
Temperature Performance

Abstract Meehanite GB300 is a pearlitic gray cast iron that has a minimum tensile strength of 300 MPa (44 ksi), when determined on test pieces machined from separately cast, 30 mm (1.2 in.) diameter test bars. This grade exhibits high strength while still maintaining good thermal conductivity and good machinability. It is generally used for applications where the thermal conductivity requirements preclude the use of other higher-strength materials, such as spheroidal graphite cast irons, which have inferior thermal properties. This datasheet provides information on physical properties, hardness, tensile properties, and compressive strength as well as fatigue. It also includes information on low and high temperature performance as well as heat treating, machining, and joining. Filing Code: CI-75. Producer or source: Meehanite Metal Corporation.

TIMETAL 829

Alloy Digest ◽  
2001 ◽  
Vol 50 (8) ◽  
Keyword(s):  
Fracture Toughness ◽  
Titanium Alloy ◽  
High Temperature ◽  
High Strength ◽  
Heat Treating ◽  
High Temperature Alloy ◽  
Turbine Engine ◽  
Major Application ◽  
Alpha Titanium ◽  
Engine Components

Abstract TIMETAL 829 is a Ti-5.5Al-3.5Sn-3Zr-1Nb-0.25Mo-0.3Si near-alpha titanium alloy that is weldable and has high strength and is a creep resistant high temperature alloy. The major application is as gas turbine engine components. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness, creep, and fatigue. It also includes information on forming and heat treating. Filing Code: TI-118. Producer or source: Timet.

SANDVIK Ti-3Al-2.5V GRADE 9

Alloy Digest ◽  
1997 ◽  
Vol 46 (9) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Endurance Limit ◽  
Weight Ratio ◽  
High Strength ◽  
Strain Ratio ◽  
Bend Strength ◽  
Aerospace Applications ◽  
Excellent Corrosion Resistance ◽  
Titanium Aluminum ◽  
Fatigue Endurance

Abstract Sandvik Ti-3Al-2.5V Grade 9 titanium-aluminum alloy offers excellent corrosion resistance, especially to chloride media, and has a high strength-to-weight ratio, which is especially suitable for use in aerospace applications. Tubing can be produced having a CSR (contractile strain ratio) that enhances the fatigue endurance limit. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and bend strength as well as fatigue. It also includes information on corrosion resistance as well as forming, machining, and joining. Filing Code: TI-109. Producer or source: Sandvik.

UNS R54620

Alloy Digest ◽  
1987 ◽  
Vol 36 (7) ◽  
Keyword(s):  
Titanium Alloy ◽  
High Temperature ◽  
Time Use ◽  
Temperature Stability ◽  
High Strength ◽  
Heat Treating ◽  
High Temperature Stability ◽  
Beta Titanium Alloy ◽  
Beta Titanium ◽  
Long Time

Abstract UNS No. R54620 is an alpha-beta titanium alloy. It has an excellent combination of tensile strength, creep strength, toughness and high-temperature stability that makes it suitable for service to 1050 F. It is recommended for use where high strength is required. It has outstanding advantages for long-time use at temperatures to 800 F. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and bend strength as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ti-86. Producer or source: Titanium alloy mills.

ATI 6-2-4-2

Alloy Digest ◽  
2020 ◽  
Vol 69 (8) ◽  
Keyword(s):  
Tensile Strength ◽  
Titanium Alloy ◽  
High Temperature ◽  
Creep Strength ◽  
High Strength ◽  
Heat Treating ◽  
Good Combination ◽  
Long Term Stability ◽  
Temperature Performance

Abstract ATI 6-2-4-2 is a near-alpha, high strength, titanium alloy that exhibits a good combination of tensile strength, creep strength, toughness, and long-term stability at temperatures up to 425 °C (800 °F). Silicon up to 0.1% frequently is added to improve the creep resistance of the alloy. This datasheet provides information on composition, physical properties, hardness, and tensile properties as well as creep. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: Ti-169. Producer or Source: ATI.

TIMETAL 685

Alloy Digest ◽  
2007 ◽  
Vol 56 (10) ◽  
Keyword(s):  
Fracture Toughness ◽  
Titanium Alloy ◽  
Shear Strength ◽  
Physical Properties ◽  
Tensile Properties ◽  
Creep Resistance ◽  
Aerospace Industry ◽  
High Strength ◽  
Heat Treating

Abstract Timetal 685 is a titanium alloy with 6 Al, 5 Zr, 0.5 Mo, and 0.25 Si. It is a near-alpha alloy with high strength and creep resistance. Applications are in the aerospace industry. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and shear strength as well as fracture toughness and creep. It also includes information on forming, heat treating, and joining. Filing Code: TI-142. Producer or source: Timet.

Sign in / Sign up

Export Citation Format

Share Document