Calculation about the Effect of Stress Concentration Coefficient on the Fatigue Properties for Welded Cruciform Joints of 16MnR Steel

2012 ◽  
Vol 189 ◽  
pp. 350-354
Author(s):  
Ying Xia Yu ◽  
Bo Lin He ◽  
Xiao Dong Zhang
Keyword(s):  
Mechanical Properties ◽  
Fatigue Life ◽  
Stress Concentration ◽  
Welded Joints ◽  
Fatigue Properties ◽  
Concentration Coefficient ◽  
Cruciform Joints ◽  
Welded Structures ◽  
Line Angle ◽  
Stress Concentration Coefficient

Stress concentration coefficient of welded joints has a crucial influence on mechanical properties of welded structures. Geometrical parameters of welded joints seriously affect the stress concentration coefficient. In order to increase the mechanical properties and safety of welded structures, it has great significance for reducing stress concentration coefficient and improving the mechanical properties of welded structures by researching and improving the geometry of welded joints. In this paper, the effect of stress concentration coefficient on the fatigue properties for welded cruciform joints of 16MnR steel was analyzed by using ABAQUS finite element and MSC.Fatigue programe, and the change rule of stress concentration coefficient with the variation of the parameter was studied and the fatigue life changed with the stress concentration coefficient was also researched. The calculation results indicate that reducing the weld tangent line angle θ can effectively decrease the stress concentration coefficient of welded cruciform joints, and the fatigue life of welded cruciform joints can be improved succesfully. In order to obtain the safety welded structures, the true weld tangent line angle θ should be controlled in the angle smaller than 20o.

Calculation about Stress Concentration Coefficient of Welded Cruciform Joints of Magnesium Alloy Based on FEM

2014 ◽  
Vol 989-994 ◽  
pp. 931-934 ◽  
Author(s):  
Bo Lin He ◽  
Ying Xia Yu ◽  
Xiao Dong Zhang ◽  
Song Song Xia
Keyword(s):  
Magnesium Alloy ◽  
Stress Concentration ◽  
Fatigue Property ◽  
Tangent Line ◽  
Concentration Coefficient ◽  
Cruciform Joints ◽  
Welded Structures ◽  
Welded Structure ◽  
Line Angle ◽  
Stress Concentration Coefficient

Geometrical parameters of welded joint affect the stress concentration coefficient seriously. In order to increase the fatigue property of welded structure, it has great significance to reduce stress concentration coefficient of welded structures by researching and improving the geometry of welded joints. In this paper, the effects of weld tangent line angle θ on the stress concentration coefficient of welded cruciform joints of magnesium alloy were analyzed by using ABAQUS finite element program, and the change rule of stress concentration coefficient with the variation of the parameter was also researched. The calculation results indicate that reducing the weld tangent line angle θ can effectively decrease the stress concentration coefficient of welded cruciform joints, so as to improve the fatigue property of welded structures. In order to have high reliability and safety of welded structures of magnesium alloy, the true weld tangent line angle θ should be controlled less than 25°.

Finite Element Calculation about Stress Concentration Coefficient of Welded Butt Joints Based on the ABAQUS

2011 ◽  
Vol 80-81 ◽  
pp. 807-811 ◽  
Author(s):  
Bo Lin He ◽  
Xiao Dong Zhang
Keyword(s):  
Mechanical Properties ◽  
Stress Concentration ◽  
Inclination Angle ◽  
Welded Joints ◽  
Concentration Coefficient ◽  
Butt Joints ◽  
Welded Structures ◽  
Weld Toe ◽  
Weld Edge ◽  
Stress Concentration Coefficient

Stress concentration coefficient of welded joints has a crucial influence on mechanical properties of welded structures. Geometrical parameters of welded joints seriously affect the stress concentration coefficient. In order to increase the mechanical properties and using safety of welded structures, it has great significance for reducing stress concentration coefficient and improving the mechanical properties of welded structures by researching and improving the geometry of welded joints . In this paper, the effect of weld toe inclination angle θ and weld edge transition arc radius r on the stress concentration coefficient of welded butt joints were analyzed by using ABAQUS finite element program, and the change rule of stress concentration coefficient with the variation of the two parameters was also researched. The calculation results indicate that reducing weld toe inclination angle or increasing transition arc radius can effectively decrease the stress concentration coefficient of welded butt joints, so as to improve the mechanical properties of welded structures. For the safe use of welded structures, the true weld edge transition arc radius r should be greater than 3mm, and weld toe inclination angle θ should be smaller than 30°.

Influence of Stress Concentration on Fatigue Property of Welded Joints of 5083 Aluminum Alloy

2013 ◽  
Vol 456 ◽  
pp. 451-455
Author(s):  
Jun Yang ◽  
Bo Li ◽  
Qiang Jia ◽  
Yuan Xing Li ◽  
Ming Yue Zhang ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Aluminum Alloy ◽  
Fatigue Strength ◽  
Stress Concentration ◽  
Welded Joints ◽  
Weld Zone ◽  
Fatigue Property ◽  
Concentration Coefficient ◽  
5083 Aluminum Alloy ◽  
Stress Concentration Coefficient

Fatigue test of the welded joint of 5083 aluminum alloy with smooth and height of specimen and the weld zone than the high test measurement and theoretical stress concentration coefficient calculation, the weld reinforcement effect of stress concentration on the fatigue performance of welded joints. The results show that: Smooth tensile strength of specimens for 264MPa, fatigue strength is 95MPa, the tensile strength of the 36%. Higher tensile strength of specimens for 320MPa, fatigue strength is 70MPa, the tensile strength of the 22%. Higher specimen stress concentration coefficient is 1.64, the stress concentration to the weld toe becomes fatigue initiation source, and reduces the fatigue strength and the fatigue life of welded joints.

Review of Status about the Effect of Ultrasonic Impact on Fatigue Properties of Welded Joints of Magnesium Alloy

2013 ◽  
Vol 668 ◽  
pp. 835-839 ◽  
Author(s):  
Ying Xia Yu ◽  
Bo Lin He ◽  
Bin Wang ◽  
Shang Yu Zhou
Keyword(s):  
Residual Stress ◽  
Grain Size ◽  
Magnesium Alloy ◽  
Welded Joints ◽  
Welded Joint ◽  
Development Trend ◽  
Fatigue Properties ◽  
Concentration Coefficient ◽  
The Development Trend ◽  
Stress Concentration Coefficient

The study on magnesium alloy has attracted attention at home and abroad. Status and development trend about the fatigue properties of welded joints of magnesium alloy were reviewed. The main problems and deficiencies were pointed out, and the recent development's focus was outlined. The development trend of improving the fatigue propeties and fatigue life was analyzed. The ultrasonic impact method can not only decrease the stress concentration coefficient and tensile residual stress of welded joint, but also refine the grain size of welded joints, even to compressive stress and nanograins. The method has put forward a new way for increasing fatigue properties and life of welded joint of magnesium alloy.

Finite Element Calculation about Stress Concentration Coefficient of Welded Butt Joints of Magnesium Alloy

2014 ◽  
Vol 989-994 ◽  
pp. 935-938
Author(s):  
Ying Xia Yu ◽  
Bo Lin He ◽  
Xiao Dong Zhang ◽  
Si Yong Lei
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Inclination Angle ◽  
Fatigue Property ◽  
Concentration Coefficient ◽  
Butt Joints ◽  
Welded Structures ◽  
Weld Toe ◽  
Weld Edge ◽  
Stress Concentration Coefficient

Geometrical parameters of welded joint affect the stress concentration coefficient seriously. In order to increase the fatigue property of welded structure, it has great significance to reduce stress concentration coefficient of welded structures by researching and improving the geometry of welded joints. In this paper, the effects of weld toe inclination angle θ and weld edge transition arc radius r on the stress concentration coefficient of welded butt joints of magnesium alloy were analyzed by using ABAQUS finite element program, and the change rule of stress concentration coefficient with the variation of the two parameters was also researched. The calculation results indicate that reducing weld toe inclination angle or increasing transition arc radius can effectively decrease the stress concentration coefficient of welded butt joints, so as to improve the fatigue property of welded structures. For the safe use of welded structures, the true weld edge transition arc radius r should be greater than 3mm, and weld toe inclination angle θ should be smaller than 30°.

The Structure and Mechanical Properties of VT23 Welded Joints with Surface Layer Modified by Ultrasonic Mechanical Forging

2017 ◽  
Vol 743 ◽  
pp. 264-268 ◽  
Author(s):  
Anastasia Smirnova ◽  
Yury Pochivalov ◽  
Victor Panin ◽  
Anatoly Orishich ◽  
Aleksandr Malikov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Fatigue Life ◽  
Welded Joints ◽  
Experimental Tests ◽  
Relaxation Property ◽  
Surface Layers ◽  
Β Phase ◽  
Fatigue Life Test ◽  
Vt23 Titanium Alloy

The structure and mechanical properties of welded joints of VT23 titanium alloy received by method of laser welding after modifying the surface layers by ultrasonic mechanical forging (Treatment 1 and Treatment 2) were investigated. The experimental tests have revealed that the Treatment 2 provides a multiple increase in the relaxation property in fatigue life test. The formation of nonuniform distribution of vanadium, chromium and molybdenum in the welded joint increases the strength and, at the same time, the brittleness of β-phase. Mechanical treatment of the surface layers in the second mode provides a multiple increase in ductility up to 13%, in the as-received condition up to 9.9%. In consequence of plastic deformation, the β-phase intensity reduces twice with Treatment 2 which is related to its clustering. As follows from a presented data, the fatigue life of the VT23 titanium alloy has increased more than threefold.

scholarly journals Stress strain state of elastic plate with elliptical cut-out

2020 ◽  
pp. 3-8
Author(s):  
E.E. Deryugin ◽  
Keyword(s):  
Plastic Deformation ◽  
Stress Concentration ◽  
Driving Force ◽  
Strain State ◽  
Mechanical State ◽  
Concentration Coefficient ◽  
Stress Strain ◽  
Crack Driving Force ◽  
Stress Strain State ◽  
Stress Concentration Coefficient

The article considers a crack in the form of a narrow cut with a certain cfn at the cut out in an unbounded plate. The characteristics of the mechanical state of this system under uniaxial loading are determined: the stress concentration coefficient, the crack-driving force, and the energy of a solid with a crack. The elastic energy expenditure during crack propagation is determined. The general regularities of the mechanical state of a solid with a crack, not necessary having the form of an ellipse, are revealed. An important parameter of a crack is the curvature at the tip. It is shown that the Griffiths crack does not actually have a singularity at the tip. The stress strain state of the plate with an elliptical crack is identical to the same of the plate with a focus of homogeneous plastic deformation.

Fatigue Properties of 3D Welded Thin Structures

2020 ◽  
Author(s):  
Seyed M. Allameh ◽  
Avery Lenihan ◽  
Roger Miller ◽  
Hadi Allameh
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Fatigue Testing ◽  
Interfacial Area ◽  
Tensile Tests ◽  
Orientation Dependence ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Mig Welding ◽  
Welded Structures

Abstract Additive manufacturing technology has matured enough to produce real industrial components. A newer method of 3D printing is the deposition of molten metal beads using a MIG weld torch. This involves a 3D printer equipped with a MIG torch layering the metals in desired shapes. It allows the fabrication of components made of MIG weld wires, currently available from various elements including Cu, Al, steel and alloys. Some of these structures made by 3D welding will have applications in critical load bearing conditions. The reliability of such components will be vital in applications where human lives are at stake. Tensile tests are conducted to verify the required strength of the fabricated parts which will undergo monotonic loading; however, fatigue tests are required for cases where cyclic loading will take place. Conventional tensile and fatigue testing requires macro-scale samples. With MIG welding, it is possible to make thin-walled structures. Fatigue testing on samples extracted from thin walls is made possible by microtesting. This study is focused on the mechanical properties of 3D welded structures made from MIG welding wires. Our earlier results showed orientation dependence of mechanical properties in 3D welded structures. They also showed the effect of substrates in expression of the orientation dependence. Welding on metal substrate produces weld beads that are harder at the substrate interfacial area. However, for structures welded on ceramics, the opposite is true. They exhibit a softer substrate interfacial area and a relatively harder top. Our newer results show fatigue properties of structures made by 3D welding. Microsamples measuring 0.2 mm × 0.2 mm × 1.0 mm were extracted from metal beads using a CNC mill along with an EDM. The contours of the samples were machined by milling and the back side was cut by electro discharge machining. Specimens were then polished to the desired size and mounted in the grippers of an E1000 Instron load frame. WaveMatrix® application software from Instron was used to control the machine and to obtain testing data. Fatigue tests were performed, and life cycles were determined for various stress levels up to over 5 million cycles. The preliminary results of tensile tests of these samples show strength levels that are comparable to those of parent metal, in the range of 600–950MPa. Results of fatigue tests show high fatigue lives associated with relatively high stresses. The preliminary results will be presented and the implications of the use of 3D welded rebar in 3D printing of reinforced concrete structures will be discussed.

scholarly journals Fatigue Life Improvement of the High Strength Steel Welded Joints by Ultrasonic Impact Peening

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 619 ◽  
Author(s):  
Ján Lago ◽  
Libor Trško ◽  
Michal Jambor ◽  
František Nový ◽  
Otakar Bokůvka ◽  
...  
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Welded Joints ◽  
Compressive Residual Stress ◽  
High Strength ◽  
Fatigue Properties ◽  
Low Alloy Steel ◽  
Residual Stress Field ◽  
Near Surface ◽  
Life Improvement

Ultrasonic impact peening was applied on welded joints manufactured from Strenx 700 MC high strength low alloy steel with the aim to improve the fatigue properties. Three different surface treatment parameters were tested, which resulted in transformation of the near-surface tensile residual stresses in the weld metal and heat affected zone to compressive residual stress field, while maximal values from −400 MPa up to −800 MPa were reached. The highest fatigue life improvement was reached by the double peening with the 85 N contact force, where the fatigue limit for N = 108 cycles increased from 370 MPa to 410 MPa.

Microstructures and Mechanical Properties of Welded Joints of Several High Tensile Strength Steel

2018 ◽  
Vol 941 ◽  
pp. 224-229
Author(s):  
Takahiro Izumi ◽  
Tatsuya Kobayashi ◽  
Ikuo Shohji ◽  
Hiroaki Miyanaga
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Weld Metal ◽  
Welded Joints ◽  
Welded Joint ◽  
Steel Plates ◽  
Fatigue Properties ◽  
High Tensile Strength ◽  
The Matrix ◽  
Microstructures And Mechanical Properties

Microstructures and mechanical properties of lap fillet welded joints of several high and ultra-high tensile strength steel by arc welding were investigated. Steel plates having tensile strength of 400 (SPH400W), 590 (SPC590Y, SPC590R), 980 (SPC980Y) and 1500 MPa (SAC1500HP) class with 2 mm thickness were prepared. Four types of joints were formed by MAG welding; SPH400W/SPH400W, SPC590Y/SPC590Y, SPC980Y/SPC980Y and SAC1500HP/SPC590R. In joints with SPC590Y, SPC980Y and SAC1500HP steel which matrixes are martensitic microstructures, the HAZ softens due to transformation of martensite into ferrite with precipitating cementite. By using high and ultra-high tensile strength steel, the weld metal is strengthened due to dilution of the matrix into the weld metal and thus tensile shear strength of the welded joint increases. In the fatigue test, similar S-N diagrams were obtained in the all welded joints investigated. It seems that the effect of stress concentration due to the shape of the welded joint on fatigue properties is larger than that of the strength of the matrix.

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