scholarly journals Effect of stress triaxiality on fracture failure of 6061 aluminium alloy

2020 ◽  
Vol 14 (2) ◽  
pp. 6961-6970
Author(s):  
L. Y. Kou ◽  
W. Y. Zhao ◽  
X. Y. Tuo ◽  
G. Wang ◽  
C. R. Sun
Keyword(s):  
Aluminum Alloy ◽  
Aluminium Alloy ◽  
Fracture Strain ◽  
Peak Load ◽  
Stress Triaxiality ◽  
Sectional Area ◽  
Cross Sectional ◽  
6061 Aluminum Alloy ◽  
Notched Specimens ◽  
6061 Aluminium Alloy

The effect of stress triaxiality on mechanical properties of 6061 aluminium alloy extruded profiles with different specimens was studied. Macroscopic mechanical property of the various specimen was got through universal testing machine. At the same time, stress triaxiality of different specimens was obtained using the method of finite element simulation. And then the fracture strain of each specimen was outputted by DIC. Fracture modes of 6061 aluminium alloy with different stress triaxiality were studied by SEM. The results show that taking tensile samples as comparison, the cross-sectional area of some notched specimens decreases and the peak load increases. Among them, the minimum cross-sectional area of the R5 central hole specimen is 20% smaller than that of the tensile sample, and the peak load is 28% larger. The fracture strain of the alloy increased with the decrease of stress triaxiality. For the same notch specimens, along the path direction, stress triaxiality of R5 notch specimens, R5 Center-hole specimens and R20 Arc notched specimens increased 47%, 17.8%, 25% respectively. According to the analysis of fracture morphology, the main fracture of 6061 aluminium alloy was ductile fracture. When the stress triaxiality is large, the dimples are small and sparsely distributed, and when the stress triaxiality is small, the dimple is large and evenly distributed. Finally, the Johnson-Cook model material parameters of 6061 aluminum alloy are fitted based on the tensile test results of different shapes of specimens, which can accurately simulate the elastic-plastic deformation and fracture instability of 6061 aluminum alloy under different stress states.

Casting of Wire Using a Twin Wheel Caster

2021 ◽  
Vol 904 ◽  
pp. 137-142
Author(s):  
Toshio Haga ◽  
Ryusei Tahara ◽  
Hisaki Watari ◽  
Shinichi Nishida
Keyword(s):  
Aluminum Alloy ◽  
Cooling Rate ◽  
Molten Metal ◽  
Outer Surface ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
6061 Aluminum Alloy ◽  
Alloy Wire ◽  
Thin Aluminum

A twin-wheel caster for casting thin aluminum alloy wire was designed, assembled, and tested. Molten metal was ejected from the nozzle (cross-sectional area: 4 mm2) of a crucible into a triangular groove that was machined on the outer surface of the lower wheel. The metal was solidified by the upper and lower wheels. Wire made of Al-1.2%Fe or 6061 aluminum alloy, whose cross-sectional area was smaller than 20 mm2, could be cast at a speed of 6 or 7 m/min. The upper and lower wheels were made of copper to increase the cooling rate. The diameter of the upper and lower wheels was 200 and 600 mm, respectively. The thickness of the wheels was 10 mm.

Casting of Thin Aluminum Alloy Rod Using Twin Wheel Caster Equipped with Rotating Side Dam Plates

2021 ◽  
Vol 1042 ◽  
pp. 61-67
Author(s):  
Toshio Haga ◽  
Naotsugu Okuda ◽  
Hisaki Watari ◽  
Shinichi Nishida
Keyword(s):  
Aluminum Alloy ◽  
Boron Nitride ◽  
Mild Steel ◽  
Molten Metal ◽  
Cross Section ◽  
Sectional Area ◽  
Cross Sectional ◽  
6061 Aluminum Alloy ◽  
Thin Aluminum ◽  
The Cross

A thin aluminum rod (width: 5 mm) was cast using a twin-wheel caster equipped with rotating side-dam plates. The upper and lower casting wheels were made of copper. The width of the flat upper and lower casting wheels was 5 mm. The rotating side-dam plate was made of mild steel. Paper 0.5 mm thick was pasted onto the plate. Boron nitride was sprayed onto the paper as an insulator and lubricant. A 6061 aluminum alloy thin rod could be cast continuously at casting speeds of 4 and 5 m/min. Molten metal was poured onto the lower wheel from a launder and conveyed into a square gap made by the lower wheel, upper wheel, and side-dam plates. The cross section of the cast rod was rectangular. The cross-sectional area of the rectangular rod was 12 to 15 mm2.

The Effects of Mn Addition on Microstructure and Properties in 6061 Aluminium Alloy

2011 ◽  
Vol 399-401 ◽  
pp. 1838-1842
Author(s):  
You Bin Wang ◽  
Jian Min Zeng
Keyword(s):  
Heat Treatment ◽  
Aluminium Alloy ◽  
X Ray Diffraction ◽  
6061 Aluminum Alloy ◽  
X Ray ◽  
T6 Heat Treatment ◽  
Hardness Tester ◽  
Mn Content ◽  
The Mean ◽  
6061 Aluminium Alloy

The effects of Mn addition on the microstructure and hardness of 6061 aluminum alloy were studied by means of scanning electron microscope (SEM) , energy dispersive X-Ray Analysis (EDX), X-ray diffraction (XRD) and hardness tester in this work. The results shows that rod and fishbone AlSiFeMn phase will be formed in the alloy with Mn addition in 6061 aluminium alloy, and the AlSiFeMn phase increases with the increasing of Mn content . By the mean of XRD, the Al4.07 Mn Si0.74 phase is found in the 6061 aluminium alloy from 0.7% to 1.5% Mn. The hardness increases with the increasing of Mn contents both for as-cast and for T6 heat treatment. However, the hardness growth rate for as-cast is much more than that for T6 heat treatment at the same Mn addition in the 6061 alloy. Mn has a little effect on the hardness for T6 heat treatment in 6061 alloy.

Effects of Stress Triaxiality on Fracture Strain of Aluminum Alloy plates

2019 ◽  
Vol 2019.68 (0) ◽  
pp. 115
Author(s):  
Slim DJEBIEN ◽  
Shinsuke NOHARA ◽  
Masahiro NISHIDA
Keyword(s):  
Aluminum Alloy ◽  
Fracture Strain ◽  
Stress Triaxiality ◽  
Effects Of Stress

Effect of Weld Defects on Tensile Properties of Lightweight Materials and Correlations With Phased Array Ultrasonic Nondestructive Evaluation

2014 ◽  
Author(s):  
Mohammad W. Dewan ◽  
M. A. Wahab ◽  
Ayman M. Okeil
Keyword(s):  
Tensile Strength ◽  
Aluminum Alloy ◽  
Tensile Properties ◽  
Phased Array ◽  
Critical Value ◽  
Area Ratio ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Strength And Toughness

Fusion welding of Aluminum and its alloys is a great challenge for the structural integrity of lightweight material structures. One of the major shortcomings of Aluminum alloy welding is the inherent existence of defects in the welded area. In the current study, tests have been conducted on tungsten inert gas (TIG) welded AA6061-T651 aluminum alloy to determine the effects of defect sizes and its distribution on fracture strength. The information will be used to establish weld acceptance/rejection criteria. After welding, all specimens were non-destructively inspected with phased array ultrasonic and measured the projected area of the defects. Tensile testing was performed on inspected specimens containing different weld defects: such as, porosity, lack of fusion, and incomplete penetration. Tensile tested samples were cut along the cross section and inspected with Optical Microscope (OM) to measure actual defect sizes. Tensile properties were correlated with phased array ultrasonic testing (PAUT) results and through microscopic evaluations. Generally, good agreement was found between PAUT and microscopic defect sizing. The tensile strength and toughness decreased with the increase of defect sizes. Small voids (area ratio <0.04) does not have significant effect on the reduction of tensile strength and toughness values. Once defective “area ratio (cross sectional area of the defect) / (total specimen cross sectional area)” reached a certain critical value (say, 0.05), both strength and toughness values decline sharply. After that critical value both the tensile strength and toughness values decreases linearly with the increase of defect area ratio.

Analysis of Size Effect in High-Cycle Fatigue for EN AW-6063

2014 ◽  
Vol 224 ◽  
pp. 75-80 ◽  
Author(s):  
Tomasz Tomaszewski ◽  
Janusz Sempruch
Keyword(s):  
Size Effect ◽  
Aluminium Alloy ◽  
High Cycle Fatigue ◽  
Specimen Size ◽  
Cross Sectional Area ◽  
Strength Testing ◽  
Sectional Area ◽  
Cycle Fatigue ◽  
Cross Sectional

Any changes in specimen size in relation to the reference dimensions involve scaling inaccuracies resulting in the variances in strength testing (monotonic, fatigue) results. It is referred to as a size effect. The size effect is described using a cross-sectional coefficient determined for various specimen sizes and test types. The analysed material is aluminium alloy EN AW-6063 T6 with a cross-sectional area of 28, 7 and 3.5 mm2.

A new ductile fracture criterion considering both shear and tension mechanisms on void coalescence

2020 ◽  
pp. 105678952096283
Author(s):  
Xifeng Li ◽  
Wenbing Yang ◽  
Dongkai Xu ◽  
Ke Ju ◽  
Jun Chen
Keyword(s):  
Aluminum Alloy ◽  
Ductile Fracture ◽  
Prediction Accuracy ◽  
Fracture Criterion ◽  
Fracture Strain ◽  
Stress Triaxiality ◽  
Void Coalescence ◽  
Ductile Fracture Criterion ◽  
New Criterion ◽  
1045 Steel

A new ductile fracture criterion is proposed based on three stages of ductile fracture: void nucleation, growth and coalescence from the microscopic viewpoint. Based on the observation of SEM fracture surfaces of AA2024-T351 aluminum alloy sheet and bar samples under different stress states, it is assumed that the void aggregation is controlled by shear or shear-tension fracture mechanism according to the stress state. And the stress triaxiality is deemed as the only influence factor for controlling the void growth. The new ductile fracture criterion applied to a wide range of stress triaxiality is built. By fitting the available testing data of AA2024-T351 aluminum alloy and AISI 1045 steel, the fracture loci in the stress triaxiality, Lode parameter and equivalent fracture strain space ([Formula: see text]) built by the new criterion are compared with those by DF2014, Hu criterion, modified Mohr-Coulomb criterion (MMC) and Hosford- Coulomb (H-C) criterion. The fitting results prove better prediction accuracy for the new criterion. To further compare the stability of these criteria, the fracture loci in the space of ([Formula: see text]) for AA2024-T351 alloy are established by only fitting five tests. The new criterion can still well predict the equivalent fracture strain ([Formula: see text]). Compared with DF2014, Hu criterion, MMC and H-C criterion, the average errors of the new criterion are reduced by 26.72%, 20.07%, 31.78% and 34.62%, respectively. Furthermore, the maximum errors are reduced by 49.62%, 27.31%, 33.76% and 29.91%, separately. Therefore, the new fracture criterion has higher prediction accuracy and better prediction stability. Last but certainly not least, the new criterion can predict more accurately under high stress triaxiality conditions.

Effect of Loading History on Elastic Modulus of HDPE

2015 ◽  
Author(s):  
P.-Y. Ben Jar
Keyword(s):  
Elastic Modulus ◽  
Stress Triaxiality ◽  
Damage Parameter ◽  
Cross Sectional Area ◽  
Test Method ◽  
Sectional Area ◽  
Loading History ◽  
Cross Sectional ◽  
Test Speed ◽  
Area Strain

This paper presents results from an experimental investigation about the influence of loading history on the elastic modulus of high-density polyethylene (HDPE). The study uses a new approach, named two-test method, to introduce the loading history using the first test and at least one month later, to measure the elastic modulus using the second test. The period of minimum one month between the two tests is to ensure that recovery of the viscous deformation from the first tests does not affect the measured elastic modulus from the second tests. Parameters considered to vary the loading history include maximum deformation (with the area strain up to 0.5 in most cases), loading mode (monotonic, cyclic and creep tension), test speed (from 0.005 to 30 mm/min), and stress triaxiality (through the change in the specimen gauge length), in which the area strain is defined as the logarithmic ratio of the original cross sectional area (i.e., the cross sectional area of virgin specimen) to the deformed cross sectional area. All of the second tests were conducted under monotonic tension at the crosshead speed of 0.001 mm/min. The results show the general trend of decrease of the elastic modulus, measured from the second tests, with the increase of the strain applied in the first tests. The results further indicate that test speed for deformation introduced in the first tests may have a significant influence on the elastic modulus measured from the second tests. The elastic modulus is used to determine damage parameter D based on the damage concept, based on influence of the loading history on the mechanical properties of HDPE is characterized.

Pelvic Canal Narrowing Caused by Triple Pelvic Osteotomy in the Dog

1994 ◽  
Vol 07 (03) ◽  
pp. 110-113 ◽  
Author(s):  
D. L. Holmberg ◽  
M. B. Hurtig ◽  
H. R. Sukhiani
Keyword(s):  
Postoperative Complications ◽  
Pelvic Osteotomy ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Canal Width ◽  
Operative Complications ◽  
Post Operative Complications

SummaryDuring a triple pelvic osteotomy, rotation of the free acetabular segment causes the pubic remnant on the acetabulum to rotate into the pelvic canal. The resulting narrowing may cause complications by impingement on the organs within the pelvic canal. Triple pelvic osteotomies were performed on ten cadaver pelves with pubic remnants equal to 0, 25, and 50% of the hemi-pubic length and angles of acetabular rotation of 20, 30, and 40 degrees. All combinations of pubic remnant lengths and angles of acetabular rotation caused a significant reduction in pelvic canal-width and cross-sectional area, when compared to the inact pelvis. Zero, 25, and 50% pubic remnants result in 15, 35, and 50% reductions in pelvic canal width respectively. Overrotation of the acetabulum should be avoided and the pubic remnant on the acetabular segment should be minimized to reduce postoperative complications due to pelvic canal narrowing.When performing triple pelvic osteotomies, the length of the pubic remnant on the acetabular segment and the angle of acetabular rotation both significantly narrow the pelvic canal. To reduce post-operative complications, due to narrowing of the pelvic canal, overrotation of the acetabulum should be avoided and the length of the pubic remnant should be minimized.

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