Evaluation of mechanical properties of polyethylene for pipes by energy approach during tensile and fatigue tests

The aim of this work is to study the effects of hydrogen absorption on mechanical properties of pipe API 5L X70 steel. This study is conducted in special soil solution NS4 with pH 6.7 It show that the tensile properties like yield stress, ultimate strength and elongation at failure reduced under hydrogen embrittlement. Several fatigue tests (three (03) points bending tests) on roman tile specimens with notch are performed. Fatigue initiation is detected by acoustic emission. A comparison between specimens electrolytically charged with hydrogen and specimens without hydrogen absorption is made and it has been noted that fatigue initiation time is reduced when hydrogen embrittlement occurs. The field of elastoplastic stresses near the notch is computed by the finite-element method with the Abaqus software package. Effective distance and stress are calculated with the volumetric approach and the Notch intensity Factor of the roman tile specimen is determined for each loading value used in our tests.

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Cyclic Mechanical Properties of 16MnR Welded Joint under Constant

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.197-198.1658 ◽

2011 ◽

Vol 197-198 ◽

pp. 1658-1661

Author(s):

Ying Xiong ◽

Han Ying Zheng

Keyword(s):

Mechanical Properties ◽

Weld Metal ◽

Endurance Limit ◽

Welded Joint ◽

Cyclic Softening ◽

Fatigue Tests ◽

Test Results ◽

Control Test ◽

Strain Control ◽

Fatigue Endurance

Fatigue tests are carried out for 16MnR welded joint under constant strain control. Test results reveal that 16MnR weld metal exhibits characteristic of cyclic softening and non-masing obviously. The strain–life curve can be best described by the three-parameter equation. It shows the fatigue endurance limit in the heat-affecting zone (HAZ) of welded joint is lower than that in the weld metal.

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Static and Cyclic Behavior of Welded DH36 Steel and Its Application at Low Temperatures

Journal of Offshore Mechanics and Arctic Engineering ◽

10.1115/1.4052179 ◽

2021 ◽

pp. 1-31

Author(s):

Weidong Zhao ◽

Guoqing Feng ◽

Bernt J. Leira ◽

Huilong Ren

Keyword(s):

Mechanical Properties ◽

Low Temperatures ◽

Fatigue Tests ◽

Cyclic Behavior ◽

Brittle Transition ◽

Ductile To Brittle Transition

Abstract The mechanical properties of welded DH36 steel at low temperatures are important to the safety of structures in Polar areas. The purpose of the study is to investigate the static and cyclic behavior of welded DH36 steel at low temperatures based on tensile and fatigue tests. The Ductile to Brittle transition and Fatigue Ductile to Brittle Transition of welded DH36 steel occurred at low temperatures. Finally, some relevant applications of the results within the context of polar engineering and design are discussed in the last part of the present study.

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Changing in Fatigue Life of 300 M Bainitic Steel After Laser Carburizing and Plasma Nitriding

MATEC Web of Conferences ◽

10.1051/matecconf/201816521002 ◽

2018 ◽

Vol 165 ◽

pp. 21002 ◽

Cited By ~ 2

Author(s):

Antonio J. Abdalla ◽

Douglas Santos ◽

Getúlio Vasconcelos ◽

Vladimir H. Baggio-Scheid ◽

Deivid F. Silva

Keyword(s):

Mechanical Properties ◽

Fatigue Life ◽

Plasma Nitriding ◽

Fatigue Behavior ◽

High Strength ◽

Tensile Tests ◽

Steel Sample ◽

Fatigue Tests ◽

300M Steel ◽

Structural Applications

In this work 300M steel samples is used. This high-strength steel is used in aeronautic and aerospace industry and other structural applications. Initially the 300 M steel sample was submitted to a heat treatment to obtain a bainític structure. It was heated at 850 °C for 30 minutes and after that, cooled at 300 °C for 60 minutes. Afterwards two types of surface treatments have been employed: (a) using low-power laser CO2 (125 W) for introducing carbon into the surface and (b) plasma nitriding at a temperature of 500° C for 3 hours. After surface treatment, the metallographic preparation was carried out and the observations with optical and electronic microscopy have been made. The analysis of the coating showed an increase in the hardness of layer formed on the surface, mainly, among the nitriding layers. The mechanical properties were analyzed using tensile and fatigue tests. The results showed that the mechanical properties in tensile tests were strongly affected by the bainitic microstructure. The steel that received the nitriding surface by plasma treatment showed better fatigue behavior. The results are very promising because the layer formed on steel surface, in addition to improving the fatigue life, still improves protection against corrosion and wear.

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Evaluation of the Heat Treatment Role for Light Aluminum Alloys Subjected to Creep and Low Cycle Fatigue

Materials Science Forum ◽

10.4028/www.scientific.net/msf.638-642.455 ◽

2010 ◽

Vol 638-642 ◽

pp. 455-460 ◽

Cited By ~ 1

Author(s):

A. Rutecka ◽

L. Dietrich ◽

Zbigniew L. Kowalewski

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Low Cycle Fatigue ◽

Numerical Models ◽

Cyclic Hardening ◽

Fatigue Tests ◽

Cycle Fatigue ◽

Lower Stress ◽

Creep Tests ◽

Different Temperatures

The AlSi8Cu3 and AlSi7MgCu0.5 cast aluminium alloys of different composition and heat treatment were investigated to verify their applicability as cylinder heads in the car engines [1]. Creep tests under the step-increased stresses at different temperatures, and low cycle fatigue (LCF) tests for a range of strain amplitudes and temperatures were carried out. The results exhibit a significant influence of the heat treatment on the mechanical properties of the AlSi8Cu3 and AlSi7MgCu0.5. An interesting fact is that the properties strongly depend on the type of quenching. Lower creep resistance (higher strain rates) and lower stress response during fatigue tests were observed for the air quenched materials in comparison to those in the water quenched. Cyclic hardening/softening were also observed during the LCF tests due to the heat treatment applied. The mechanical properties determined during the tests can be used to identify new constitutive equations and to verify existing numerical models.

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Development in mechanical and fatigue properties of AA6061/AL2O3 nanocomposites under stirring temperature (ST)

Eastern-European Journal of Enterprise Technologies ◽

10.15587/1729-4061.2021.238588 ◽

2021 ◽

Vol 4 (12(112)) ◽

pp. 47-52

Author(s):

Raad Mohammed Abed ◽

Ali Yousuf Khenyab ◽

Hussain Jasim M. Alalkawi

Keyword(s):

Mechanical Properties ◽

Cost Effective ◽

Fatigue Tests ◽

Core Material ◽

Fatigue Properties ◽

Uniform Distributions ◽

Al2o3 Composite ◽

Structural Applications ◽

The Matrix ◽

High Fatigue

Aluminum is expected to remain the core material for many critical applications such as aircraft and automobiles. This is due to the high resistance to different environmental conditions, desired and manageable mechanical properties, as well as high fatigue resistance. Aluminum nanocomposites such as AA6061/Al2O3 can be made in many ways using a liquid metallurgy method. The main challenges for this method in the production of nanocomposites are the difficulties of achieving a uniform distribution of reinforcing materials and possible chemical reactions between the reinforcing material and the matrix. For structural applications exclusive to aerospace sectors. The growing cost-effective nanocomposites mass production technology with essential operational and geometric flexibility is a big challenge all the time. Each method of preparing AA6061/Al2O3 nanocomposites can provide different mechanical properties. In the present study, nine nanocomposites were prepared at three stirring temperatures (800, 850, and 900 °C) with the level of Al2O3 addition of 0, 5, 7, and 9 wt %. The results of tensile, hardness and fatigue tests revealed that the composite including 9 wt % Al2O3 with 850 °C stirring temperatures has the best properties. It was also revealed that the 850 °C stirring temperature (ST) with 9 wt % Al2O3 composite provide an increase in tensile strength, VHN and reduction in ductility by 20 %, 16 % and 36.8 % respectively, compared to zero-nano. Also, the fatigue life at the 90 MPa stress level increased by 17.4 % in comparison with 9 wt % nanocomposite at 800 °C (ST). Uniform distributions were observed for all nine microstructure compositions.

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Mechanical Properties of Flat Braided Composites With a Circular Hole

10.1115/imece1999-0512 ◽

1999 ◽

Author(s):

Takeru Ohki ◽

Shinya Ikegaki ◽

Ken Kurasiki ◽

Hiroyuki Hamada ◽

Masaharu Iwamoto

Keyword(s):

Mechanical Properties ◽

Tensile Test ◽

Circular Hole ◽

Fracture Behavior ◽

Fatigue Property ◽

Tensile Tests ◽

Fatigue Tests ◽

Braided Composites ◽

Static Tensile ◽

The One

Abstract In this study, fracture behavior and strength in the flat braided bar with a circular hole were investigated by static and fatigue test. Two type of specimens were prepared. They are a braided flat bar with an integrally-formed braided hole and a braided flat bar with a machined hole. Moreover, we also examined a specimen that had a metal pin inserted at the circular hole. This specimen was subjected to a static tensile test. The results of the tensile tests indicate that the strength of the flat bar with a braided hole was larger than that of the one with the machined hole. Furthermore, from the results of the fatigue tests, the flat bar with the braided hole showed higher fatigue property than that of the one with the machined hole.

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Fatigue Properties of 3D Welded Thin Structures

Volume 12: Mechanics of Solids, Structures, and Fluids ◽

10.1115/imece2020-23135 ◽

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.

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Fatigue Characteristics and Numerical Modeling Socket for Patient with above Knee Prosthesis

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.398.76 ◽

2020 ◽

Vol 398 ◽

pp. 76-82 ◽

Cited By ~ 1

Author(s):

Saif M. Abbas

Keyword(s):

Mechanical Properties ◽

Carbon Fiber ◽

Safety Factor ◽

Knee Prosthesis ◽

Fatigue Tests ◽

Interface Pressure ◽

Prosthetic Socket ◽

Glass Carbon ◽

Fatigue Characteristics ◽

Test Result

In this research, two groups of composite materials were used for manufacturing Above –Knee (AK) prosthetic socket. These sockets were fabricated from resin lamination (80:20) siegalharz as matrix materials, N-glass and carbon as reinforced materials using vacuum pressure. The mechanical properties for materials that used in above knee socket were tested by tensile, bending and fatigue tests. The results showed the mechanical properties of (N-glass - carbon fiber-N-glass) with matrix of lamination (80:20) resin were: Ϭy= 112Mpa, Ϭult=132MPa, Ϭb max=57Mpa, E=1.74GPa and The elongation at Beak was 3.5mm. In addition, the test result of (N-glass - carbon fiber-N-glass) with matrix of siegalharz resin were Ϭy= 123Mpa, Ϭult=151MPa, Ϭb max=174Mpa, E=2.64GPa and the elongation at Beak was3.3mm. Interface pressure was measured for above knee prosthetic socket and the patient age (30years) , height (165 cm) and weight (83 kg). High pressure values of (190Kpa) and (164Kpa) were recorded for the anterior and lateral sections respectively. This is because of the anterior and lateral muscles action which tend to be more active during the movement of the patient. The numerical results showed that the safety factor for (N-glass - carbon fiber-N-glass) with matrix lamination of (80:20) resin was found to be 0.595in addition the safety factor for (N-glass - carbon fiber-Nglass) with matrix of siegalharz resin was numerically calculated to be 1.084 which is safe in design.

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Effect of FSW Traverse Speed on Mechanical Properties of Copper Plate Joints

Materials ◽

10.3390/ma13081937 ◽

2020 ◽

Vol 13 (8) ◽

pp. 1937 ◽

Cited By ~ 2

Author(s):

Tomasz Machniewicz ◽

Przemysław Nosal ◽

Adam Korbel ◽

Marek Hebda

Keyword(s):

Mechanical Properties ◽

Friction Stir Welding ◽

Rolling Direction ◽

Base Material ◽

Traverse Speed ◽

Travel Speed ◽

Fatigue Tests ◽

Copper Plate ◽

Friction Stir ◽

Microstructural Evaluation

The paper describes the influence of the friction stir welding travel speed on the mechanical properties of the butt joints of copper plates. The results of static and fatigue tests of the base material (Cu-ETP R220) and welded specimens produced at various travel speeds were compared, considering a loading applied both parallel and perpendicularly to the rolling direction of the plates. The mechanical properties of the FSW joints were evaluated with respect to parameters of plates’ material in the delivery state and after recrystallisation annealing. The strength parameters of friction stir welding joints were compared with the data on tungsten inert gas welded joints of copper plates available in the literature. The results of microhardness tests and fractographic analysis of tested joints are also presented. Based on the above test results, it was shown that although in the whole range of considered traverse speeds (from 40 to 80 mm/min), comparable properties were obtained for FSW copper joints in terms of their visual and microstructural evaluation, their static and especially fatigue parameters were different, most apparent in the nine-fold greater observed average fatigue life. The fatigue tests turned out to be more sensitive criteria for evaluation of the FSW joints’ qualities.

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