Growing and critical ovalization for sharp-notched 6061-T6 aluminum alloy tubes under cyclic bending

2016 ◽  
Vol 39 (8) ◽  
pp. 926-935
Author(s):  
Kuo-Long Lee ◽  
Chen-Cheng Chung ◽  
Wen-Fung Pan
Keyword(s):  
Aluminum Alloy ◽  
Cyclic Bending

scholarly journals Variation of the 90° Redundant-hole Diameter Effect on the Response and Failure of Round-hole 6061-T6 Aluminum Alloy Tubes under the Cyclic Bending

2020 ◽  
Vol 9 (4) ◽  
pp. 187-195
Author(s):  
Kuo-Long Lee ◽  
Wen-Fung Pan
Keyword(s):  
Aluminum Alloy ◽  
Analytical Data ◽  
Bending Moment ◽  
Hole Diameter ◽  
Round Hole ◽  
Cyclic Bending ◽  
Straight Lines ◽  
Aluminum Alloy Tube ◽  
Diameter Effect ◽  
Good Agreement

This paper presents an experiment and an analysis for examining the variation of the 90° redundant-hole diameter effect on the cyclic bending mechanical behavior and fracture failure of round-hole 6061-T6 aluminum alloy tubes. In this investigation, a round-hole 6061-T6 aluminum alloy tube with a 6 mm hole diameter was drilled to obtain a 90° redundant hole but with different hole diameter of 2, 4, 6, 8, or 10 mm. It can be observed that from the first bending cycle, the bending moment-curvature curve describes a stable loop. The diameter of the 90° redundant hole has little effect on the bending moment-curvature relationship. However, when the number of bending cycles increases, the ovalization-curvature curve shows an increasing, asymmetrical, ratcheting, and bow-like tendency. The diameter of 90° redundant-hole shows a significant influence on the ovalization-curvature relationship. In addition, five non-parallel straight lines corresponding to five different 90° redundant hole diameters were discovered for the controlled curvature-number of bending cycles necessary to cause failure relationship on the double logarithmic coordinates. Finally, a formula was presented to simulate the above relationship. It is found that the experimental and analytical data were in good agreement.

Collapse of Sharp-Notched 6061-T6 Aluminum Alloy Tubes Under Cyclic Bending

2016 ◽  
Vol 16 (07) ◽  
pp. 1550035 ◽  
Author(s):  
Chen-Cheng Chung ◽  
Kuo-Long Lee ◽  
Wen-Fung Pan
Keyword(s):  
Finite Element ◽  
Aluminum Alloy ◽  
Cyclic Bending ◽  
Finite Element Software ◽  
Buckling Failure ◽  
Simulation Results ◽  
Number Of Cycles ◽  
The Moment ◽  
The Relationship ◽  
Good Agreement

The mechanical behavior and buckling failure of sharp-notched 6061-T6 aluminum alloy tubes with different notch depths subjected to cyclic bending are experimentally and theoretically investigated. The experimental moment–curvature relationship exhibits an almost steady loop from the beginning of the first cycle. However, the ovalization–curvature relationship exhibits a symmetrical, increasing, and ratcheting behavior as the number of cycles increases. The six groups of tubes tested have different notch depths, from which two different trends can be observed from the relationship between the controlled curvature and the number of cycles required to ignite buckling. Finite element software ANSYS is used to simulate the moment–curvature and ovalization–curvature relationships. Additionally, a theoretical model is proposed for simulation of the controlled curvature-number of cycles concerning the initiation of buckling. Simulation results are compared with experimental test data, which shows generally good agreement.

scholarly journals Experimental Study of Cyclic Bending Failure for Round-hole Tubes with a Redundant Round Hole in the Same Direction but Different Cross Sections

2020 ◽  
Vol 9 (2) ◽  
pp. 83-92
Author(s):  
Kuo-Long Lee ◽  
Wen-Fung Pan
Keyword(s):  
Aluminum Alloy ◽  
Cross Sections ◽  
Hole Diameter ◽  
Round Hole ◽  
Cyclic Bending ◽  
Number Of Cycles ◽  
The Moment ◽  
Straight Lines ◽  
Bending Failure ◽  
Good Agreement

This paper presents the influence of a redundant round hole in the same direction but different cross sections on the response and failure of round-hole 6061-T6 aluminum alloy tubes subjected to cyclic bending. In this study, round-hole 6061-T6 aluminum alloy tubes with a constant hole diameter of 6 mm were drilled to obtain a redundant round hole in the same hole direction but different cross sections. The experimental results revealed that the moment–curvature relationship exhibited an almost steady loop from the beginning of the first cycle. The redundant round hole showed minimal influence on the moment–curvature relationship. However, the ovalization–curvature relationship demonstrated an asymmetrical, increasing, ratcheting and bow pattern along with the bending cycle, while the redundant round hole showed a significant influence on this relationship. In addition, six groups of round-hole 6061-T6 aluminum alloy tubes were tested, the controlled curvature-number of bending cycles required to ignite failure relationships on double logarithmic coordinates exhibited nonparallel straight lines. Finally, a theoretical model was proposed for simulating the controlled curvature–number of cycles to ignite failure. The simulation result was compared with experimental test data, which showed generally good agreement.

Techniques for Transmission Electron Microscopy of Fiber-Matrix Interfaces in Aluminum Alloy-Boron Composites by Ion Erosio

1971 ◽  
Vol 29 ◽  
pp. 204-205
Author(s):  
G. G. Shaw
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Aluminum Alloy ◽  
Electron Beam ◽  
Pure Aluminum ◽  
Ion Milling ◽  
Transmission Electron ◽  
Fiber Matrix ◽  
Ion Erosion ◽  
Row Of Fibers

The morphology and composition of the fiber-matrix interface can best be studied by transmission electron microscopy and electron diffraction. For some composites satisfactory samples can be prepared by electropolishing. For others such as aluminum alloy-boron composites ion erosion is necessary.When one wishes to examine a specimen with the electron beam perpendicular to the fiber, preparation is as follows: A 1/8 in. disk is cut from the sample with a cylindrical tool by spark machining. Thin slices, 5 mils thick, containing one row of fibers, are then, spark-machined from the disk. After spark machining, the slice is carefully polished with diamond paste until the row of fibers is exposed on each side, as shown in Figure 1.In the case where examination is desired with the electron beam parallel to the fiber, preparation is as follows: Experimental composites are usually 50 mils or less in thickness so an auxiliary holder is necessary during ion milling and for easy transfer to the electron microscope. This holder is pure aluminum sheet, 3 mils thick.

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