scholarly journals Mean curvature effect on the response and failure of round-hole tubes submitted to cyclic bending

2021 ◽  
Vol 13 (11) ◽  
pp. 168781402110622
Author(s):  
Kuo-Long Lee ◽  
Yu-Chun Tsai ◽  
Wen-Fung Pan
Keyword(s):  
Mean Curvature ◽  
Hole Diameter ◽  
Experimental Results ◽  
Round Hole ◽  
Curvature Effect ◽  
Cyclic Bending ◽  
The Mean ◽  
The Moment ◽  
Straight Lines ◽  
Minimum Curvature

This paper presents an experiment and analysis to investigate the response and failure of 6061-T6 aluminum alloy round-hole tubes with different hole diameters of 2, 4, 6, 8, and 10 mm subjected to cyclic bending at different curvature ratios of −1.0, −0.5, 0.0, and +0.5. The curvature ratio is defined as the minimum curvature divides by the maximum curvature. Four different curvature ratios are employed to highlight the mean curvature effect. It can be seen from the experimental results that the moment-curvature relationships gradually relax and become steady states after a few bending cycles for curvature ratios of −0.5, 0.0, and +0.5. The ovalization-curvature relationship depicts an asymmetrical, ratchetting and increasing as the number of bending cycles increases for all curvature ratios. In addition, for each hole diameter, the relationships between the curvature range and the number of bending cycles necessary to initiate failure on double logarithmic coordinates display four almost-parallel straight lines for four different curvature ratios. Finally, this paper introduces an empirical formula to simulate the above relationships. By comparing with experimental results, the analysis can reasonably describe the experimental results.

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.

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.

Vibratory Feeding by Nonsinusoidal Vibration—Optimum Wave Form

1985 ◽  
Vol 107 (2) ◽  
pp. 188-195 ◽  
Author(s):  
S. Okabe ◽  
Y. Kamiya ◽  
K. Tsujikado ◽  
Y. Yokoyama
Keyword(s):  
Experimental Results ◽  
Wave Form ◽  
Velocity Wave ◽  
The Mean ◽  
Straight Lines ◽  
Vibratory Conveyor ◽  
Theoretical Results ◽  
Vibratory Feeding

This paper presents the conveying velocity on a vibratory conveyor whose track is vibrated by nonsinusoidal vibration. The velocity wave form of the vibrating track is approximated by six straight lines, and five distortion factors of the wave form are defined. Considering the modes of motion of the particle, the mean conveying velocity is calculated for various conditions. Referring to these results, the optimum wave form is clarified analytically. The theoretical results show that the mean conveying velocity is considerably larger than that of ordinary feeders if the proper conveying conditions are chosen. The theoretical results are confirmed by experimental results.

scholarly journals The properties of torsional vibrations in reciprocating engine shafts. —Part II

1926 ◽  
Vol 113 (764) ◽  
pp. 272-281 ◽  
Keyword(s):  
Moment Of Inertia ◽  
Experimental Results ◽  
Effective Length ◽  
Torsional Vibrations ◽  
Static Tests ◽  
Reciprocating Engine ◽  
The Mean ◽  
The Moment

In order to compare with the experimental results, the algebraic values of the results just obtained will be converted into numbers, using the dimensions adopted in the experiment. The shaft used was a steel rod ⅜-inch in diameter. From the contact of fly-wheel A to that of fly-wheel E was 78¾ inches, and from fly-wheel A to the crank (see fig. 1) was 81¼ inches. The mean of these, or 80 inches, was takenas the effective length. The modulus of rigidity, taken from static tests, was found to be 11.4 x 10 6 lbs. per square inch. The moment of inertia of fly-wheel A was about 15,000 lbs. (inches) 2 . The fly-wheel E was tested experimentally, and its moment of inertia found to be 194·2 lbs. (inches) 2 . The crank radius, a , was 2 inches.

scholarly journals Response of round-hole tubes submitted to pure bending creep and pure bending relaxation

2021 ◽  
Vol 13 (9) ◽  
pp. 168781402110491
Author(s):  
Kuo-Long Lee ◽  
Bo-You Liu ◽  
Wen-Fung Pan
Keyword(s):  
Experimental Study ◽  
Aluminum Alloy ◽  
Theoretical Analysis ◽  
Research Team ◽  
Hole Diameter ◽  
Thickness Ratio ◽  
Experimental Results ◽  
Round Hole ◽  
Pure Bending ◽  
Time Relationship

This paper presents experimental study on the response of 6061-T6 aluminum alloy round-hole tubes with five different hole diameters of 2, 4, 6, 8, and 10 mm and four different diameter-to-thickness ratios of 30, 40, 50, and 60 submitted to pure bending creep and pure bending relaxation. Pure bending creep or relaxation is defined as bending the tube to the required moment or curvature and maintaining that moment or curvature for a period of time. The experimental results of pure bending creep show that the curvature increases with time. In addition, larger holding moment, diameter-to-thickness ratio, or hole diameter results in larger creep curvature. As the curvature continues to increase, the round-hole tube eventually breaks. The experimental results of pure bending relaxation show that the relaxation moment decreases sharply with time and tends to a stable value. In addition, larger holding curvature, diameter-to-thickness ratio, or hole diameter results in larger drop of the relaxation moment. Due to fixed curvature, the round-hole tube does not break. Finally, formulas proposed by the research team of Pan et al. were respectively improved to simulate the creep curvature-time relationship for pure bending creep in the initial and the secondary stages and the relaxation moment-time for pure bending relaxation. After comparing with the experimental results, it is found that theoretical analysis can reproduce the experimental results reasonably.

Effect of Vulcanization and Shaping Process on Radial Force Variation of TBR Tire

2009 ◽  
Vol 87-88 ◽  
pp. 504-508
Author(s):  
Ping Fu ◽  
Chuan Sheng Wang ◽  
De Wei Zhang ◽  
Hui Guang Bian ◽  
Zhe Pu
Keyword(s):  
Radial Force ◽  
Hole Diameter ◽  
Experimental Results ◽  
Shaping Process ◽  
Force Variation ◽  
The Moment ◽  
Base Data

The study was based on researching various parameter of vulcanization shaping process for effect of radial force variation (RFV).The experimental results showed that reducing the first and second shaping pressure, and increasing hole diameter of N2 on curing bladder, and extending times of discharged N2 in shaping process, and reducing pressure of expanded bladder at the moment of closing mold, could reduce RFV of TBR tire and improve uniformity of tire and provide base data of product process.

scholarly journals Evolution of the first eigenvalue of the Laplace operator and the p-Laplace operator under a forced mean curvature flow

2020 ◽  
Vol 18 (1) ◽  
pp. 1518-1530
Author(s):  
Xuesen Qi ◽  
Ximin Liu
Keyword(s):  
Laplace Operator ◽  
Mean Curvature ◽  
Mean Curvature Flow ◽  
Curvature Flow ◽  
Second Fundamental Form ◽  
Coefficient Function ◽  
First Eigenvalue ◽  
Initial Hypersurface ◽  
The Mean ◽  
The Laplace Operator

Abstract In this paper, we discuss the monotonicity of the first nonzero eigenvalue of the Laplace operator and the p-Laplace operator under a forced mean curvature flow (MCF). By imposing conditions associated with the mean curvature of the initial hypersurface and the coefficient function of the forcing term of a forced MCF, and some special pinching conditions on the second fundamental form of the initial hypersurface, we prove that the first nonzero closed eigenvalues of the Laplace operator and the p-Laplace operator are monotonic under the forced MCF, respectively, which partially generalize Mao and Zhao’s work. Moreover, we give an example to specify applications of conclusions obtained above.

scholarly journals Helium, [Fe/H] Abundances and the HR (Log TEFF, MBol) Diagram With Hipparcos Data of The Four Nearest Open Clusters: Hyades, Coma Berenices, The Pleiades and Praesepe

1998 ◽  
Vol 11 (1) ◽  
pp. 565-565
Author(s):  
G. Cayrel de Strobel ◽  
R. Cayrel ◽  
Y. Lebreton
Keyword(s):  
Main Sequence ◽  
Open Clusters ◽  
Main Sequence Stars ◽  
Spectroscopic Analyses ◽  
Solar Metallicity ◽  
Metal Abundances ◽  
The Mean ◽  
The Moment ◽  
The One ◽  
Best Fit

After having studied in great detail the observational HR diagram (log Teff, Mbol) composed by 40 main sequence stars of the Hyades (Perryman et al.,1997, A&A., in press), we have tried to apply the same method to the observational main sequences of the three next nearest open clusters: Coma Berenices, the Pleiades, and Praesepe. This method consists in comparing the observational main sequence of the clusters with a grid of theoretical ZAMSs. The stars composing the observational main sequences had to have reliable absolute bolometric magnitudes, coming all from individual Hipparcos parallaxes, precise bolometric corrections, effective temperatures and metal abundances from high resolution detailed spectroscopic analyses. If we assume, following the work by Fernandez et al. (1996, A&A,311,127), that the mixing-lenth parameter is solar, the position of a theoretical ZAMS, in the (log Teff, Mbol) plane, computed with given input physics, only depends on two free parameters: the He content Y by mass, and the metallicity Z by mass. If effective temperature and metallicity of the constituting stars of the 4 clusters are previously known by means of detailed analyses, one can deduce their helium abundances by means of an appropriate grid of theoretical ZAMS’s. The comparison between the empirical (log Teff, Mbol) main sequence of the Hyades and the computed ZAMS corresponding to the observed metallicity Z of the Hyades (Z= 0.0240 ± 0.0085) gives a He abundance for the Hyades, Y= 0.26 ± 0.02. Our interpretation, concerning the observational position of the main sequence of the three nearest clusters after the Hyades, is still under way and appears to be greatly more difficult than for the Hyades. For the moment we can say that: ‒ The 15 dwarfs analysed in detailed in Coma have a solar metallicity: [Fe/H] = -0.05 ± 0.06. However, their observational main sequence fit better with the Hyades ZAMS. ‒ The mean metallicity of 13 Pleiades dwarfs analysed in detail is solar. A metal deficient and He normal ZAMS would fit better. But, a warning for absorption in the Pleiades has to be recalled. ‒ The upper main sequence of Praesepe, (the more distant cluster: 180 pc) composed by 11 stars, analysed in detail, is the one which has the best fit with the Hyades ZAMS. The deduced ‘turnoff age’ of the cluster is slightly higher than that of the Hyades: 0.8 Gyr instead of 0.63 Gyr.

scholarly journals Contour Detection for Fibre of Preserved Szechuan Pickle Based on Dilated Convolution

2019 ◽  
Vol 9 (13) ◽  
pp. 2684 ◽  
Author(s):  
Hongyang Li ◽  
Lizhuang Liu ◽  
Zhenqi Han ◽  
Dan Zhao
Keyword(s):  
Edge Detection ◽  
State Of The Art ◽  
Contour Detection ◽  
Experimental Results ◽  
Contour Method ◽  
Class Differences ◽  
Dilated Convolution ◽  
The Mean ◽  
Art Performance

Peeling fibre is an indispensable process in the production of preserved Szechuan pickle, the accuracy of which can significantly influence the quality of the products, and thus the contour method of fibre detection, as a core algorithm of the automatic peeling device, is studied. The fibre contour is a kind of non-salient contour, characterized by big intra-class differences and small inter-class differences, meaning that the feature of the contour is not discriminative. The method called dilated-holistically-nested edge detection (Dilated-HED) is proposed to detect the fibre contour, which is built based on the HED network and dilated convolution. The experimental results for our dataset show that the Pixel Accuracy (PA) is 99.52% and the Mean Intersection over Union (MIoU) is 49.99%, achieving state-of-the-art performance.

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