scholarly journals Multi-step Hydroforming Process And Wall Thickness Optimization of 5A02 Aluminum Alloy Five-Way Tube With Different Branch Diameter

2021 ◽  
Author(s):  
Liming Wei ◽  
Xuefeng Xu ◽  
Yubin Fan ◽  
Ju Zhang ◽  
Congcong Yuan
Keyword(s):  
Aluminum Alloy ◽  
Wall Thickness ◽  
Large Diameter ◽  
Tube Hydroforming ◽  
Reduction Rate ◽  
Small Diameter ◽  
Branch Diameter ◽  
Hydroforming Process ◽  
One Step ◽  
The One

Abstract The different branch diameter of five-way tube affects the design of loading internal pressure in the hydroforming process, where the large-diameter branch is broken more easily than the small-diameter one due to the same ultimate stress of tube material in one-step forming method. Therefore, the first four-way and then five-way of multi-step forming (FFTF) method and the first three-way and then five-way of multi-step forming (FTTF) method were proposed to fabricate the 5A02 aluminum alloy five-way tube with two kinds of branch diameters to avoid the burst of large-diameter branch tube. The finite element simulation of five-way tube hydroforming process shows that the height of small-diameter branch tube is lower and serious wrinkles appear at the large-diameter branch tube in the one-step forming and FFTF method. By optimizing the length of punch, a five-way tube with a big branch height and uniform wall thickness was obtained with the FTTF method. The approach of lengthening the punch in the experiment increased the height of formed branch and reduced the wall thickness reduction rate of five-way tube in FTTF method. Overall, the findings mentioned above can not only offer guide in creating five-way tube with excellent quality, but also be taken as reference to the hydroforming studies on multi-way tube in the future.

Reliability-Based Limit States Design for Onshore Pipelines

2002 ◽  
Author(s):  
Maher Nessim ◽  
Tom Zimmerman ◽  
Alan Glover ◽  
Martin McLamb ◽  
Brian Rothwell ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Traditional Approach ◽  
Large Diameter ◽  
Small Diameter ◽  
Mechanical Damage ◽  
Design Approach ◽  
Design Parameters ◽  
Pipe Failure ◽  
Limit States ◽  
Current Design

The traditional approach to pipelines design is to select a wall thickness that maintains the hoop stress below the yield strength multiplied by a safety factor. The main design condition implied by this approach is yielding (and by extension burst) of the defect-free pipe. Failure statistics show that this failure mode is virtually impossible as the majority of failures occur due to equipment impact and various types of defects such as corrosion and cracks. Recent investigations show that these failure causes are much more sensitive to wall thickness than to steel grade. As a consequence, current design methods produce variable levels of safety for different pipelines — small-diameter, low-pressure pipelines for example have been shown to have higher failure risks due to mechanical damage than large-diameter, high-pressure pipelines. In addition, the current design approach has been shown to have limited ability to deal with new design parameters, such high steel grades, and unique loading conditions such as frost heave and thaw settlement. The paper shows how these limitations can be addressed by adopting a reliability-based limit states design approach. In this approach, a pipeline is designed to maintain a specified reliability level with respect to its actual expected failure mechanisms (known as limit states). Implementation involves identifying all relevant limit states, selecting target reliability levels that take into account the severity of the failure consequences, and developing a set of design conditions that meet the target reliability levels. The advantages of this approach include lower overall cost for the same safety level, more consistent safety across the range of design parameters, and a built-in ability to address new design situations. Obstacles to its application for onshore pipelines include lack of familiarity with reliability-based approaches and their benefits and lack of consensus on how to define reliability targets. The paper gives an overview of the reliability-based design approach and demonstrates its application using an example involving design for mechanical damage.

scholarly journals Laser Irradiation-Hindered Growth of Small-Diameter Single-Walled Carbon Nanotubes by Chemical Vapor Deposition

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Yunlei Fu ◽  
Xiuyun Zhang ◽  
Chunfeng Lao ◽  
Danhong Shang ◽  
Maoshuai He
Keyword(s):  
Laser Irradiation ◽  
Vapor Deposition ◽  
Supported Catalysts ◽  
Large Diameter ◽  
Small Diameter ◽  
Chemical Vapor ◽  
Single Walled Carbon Nanotubes ◽  
The One ◽  
Walled Carbon Nanotubes ◽  
Swnt Growth

SWNTs are synthesized on a Co/MgO catalyst using “laser-disturbed” CVD with CO as the carbon source. Compared with SWNTs grown by thermal CVD without laser irradiation (normal CVD), SWNTs synthesized under laser irradiation demonstrate the suppression of small-diameter SWNT growth, as indicated by Raman spectroscopy. Such a phenomenon is also observed for other supported catalysts, such as Co/SiO2 and Fe/MgO. Controlled experiments were carried out to clarify the effects of lasers. On the one hand, laser irradiation increases the reaction temperature locally, favoring the growth of SWNTs at a set temperature as low as 350°C. On the other hand, laser irradiation inhibits the nucleation of small SWNT caps, leading to the growth of large-diameter SWNT species. This work opens a new avenue for growing SWNTs with controlled diameters.

Comparison of hairtube types for the detection of mammals

1999 ◽  
Vol 26 (6) ◽  
pp. 745 ◽  
Author(s):  
D. B. Lindenmayer ◽  
R. D. Incoll ◽  
R. B. Cunningham ◽  
M. L. Pope ◽  
C. F. Donnelly ◽  
...  
Keyword(s):  
Large Diameter ◽  
Small Diameter ◽  
Detection Rates ◽  
South Wales ◽  
Wide Range ◽  
Mountain Ash ◽  
Common Wombat ◽  
Antechinus Stuartii ◽  
Pvc Pipe ◽  
The One

We compare detection rates of different species of mammals by three types of hairtubes in both the mountain ash forests of the central highlands of Victoria and a range of wet forest types at Tumut in southern New South Wales. The types of hairtubes were a small-diameter PVC pipe, a large-diameter PVC pipe and a newly constructed tapered hair funnel. Data were analysed for brown antechinus (Antechinus stuartii), bush rat (Rattus fuscipes), common wombat (Vombatus ursinus), swamp wallaby (Wallabia bicolor) and common and mountain brushtail possums (Trichosurus vulpecula and T. caninus). The most effective hairtube type (i.e. the one yielding the highest number of detections) varied between species: small hairtubes forR. fuscipes, hair funnels for Trichosurus spp., and large hairtubes for V. ursinus and W. bicolor. For A. stuartii, the most effective hairtube type differed between the two study regions (hair funnels in Victoria and small hairtubes at Tumut). Detection by more than one hairtube type at a given plot was uncommon. Our findings have important implications for field surveys and how data gathered from such studies are interpreted. For example, if the aim of field survey is to detect a wide range of species then several types of hairtubes may need to be deployed.

Effect of Heat Treatment Conditions on Tube Hydroforming Characteristics of Aluminum Alloy

2013 ◽  
Vol 535-536 ◽  
pp. 275-278
Author(s):  
Myeong Han Lee ◽  
Young Chul Shin ◽  
Duk Jae Yoon
Keyword(s):  
Heat Treatment ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Metal Forming ◽  
Tube Hydroforming ◽  
Treatment Processes ◽  
Forming Technology ◽  
Treatment Conditions ◽  
Compressive Loads ◽  
Hydroforming Process

Tube hydroforming is a metal forming technology that utilizes internal pressure and axial compressive loads to generate designed product shapes with complex sections from tubular materials. The tube hydroforming process has been used in the automotive, aircraft, and bicycle industries for many years. With the pursuit of lighter bicycles, aluminum alloys have been utilized as an alternative to steel. To obtain adequate strength, the aluminum alloys should undergo heat treatment processes before being used. However, the mechanical properties of the alloys vary with the tempering conditions. This paper aims to evaluate the effects of tube hydroforming characteristics on different kinds of tempered aluminum alloys. Based on numerical simulations, suitable tube hydroforming processing conditions for each tempered aluminum alloy are suggested.

Design and simulation of inductive coupler based on Ni–Zn ferrites

2019 ◽  
Vol 33 (16) ◽  
pp. 1950180
Author(s):  
Meng-Han Zhao ◽  
Xiu-Li Fu
Keyword(s):  
Large Diameter ◽  
Small Diameter ◽  
Magnetic Core ◽  
Power Line ◽  
Structure Model ◽  
Power Line Carrier ◽  
Key Technologies ◽  
Low Insertion Loss ◽  
The One ◽  
Selection Of

The main purpose of this work is to couple the transmission signal into the power line with a low insertion loss. The inductive coupler is simulated by using CST modeling. By means of the non-contact inductive coupler, the carrier signals on the wire with large diameter are coupled into the one with small diameter and then enter the power line carrier handling veneer, so as to realize the coupled transmission of the signals. The structure model of the inductive coupler is established, in which the key technologies are the selection of magnetic core materials and the design of the coupler structure.

Effect of vessel diameter on variation of fiber morphology in Acacia mangium

IAWA Journal ◽  
2020 ◽  
Vol 41 (1) ◽  
pp. 2-11
Author(s):  
Ridwan Yahya ◽  
Yansen Yansen ◽  
Suyako Tazuru-Mizuno ◽  
Junji Sugiyama
Keyword(s):  
Wall Thickness ◽  
Fiber Diameter ◽  
Large Diameter ◽  
Small Diameter ◽  
Cell Diameter ◽  
Fiber Morphology ◽  
Fiber Cells ◽  
Small Vessels ◽  
Fiber Wall ◽  
Large Vessels

Abstract Paper quality depends on fiber diameter and wall thickness, and their derivatives. Fiber deformation occurs due to pressure from the vessel during development. The diameter and wall thickness of the fibers were measured following the direction of pressure exerted by the vessel on the face of the fiber cells. Fiber cell diameter measured perpendicular to and parallel with vessel enlargement was referred to as radial and tangential diameter, respectively, and likewise for fiber wall thickness. Differences in radial and tangential diameter and wall thickness of fiber cells in relation to their distance from vessels were analyzed. The radial diameter of fibers adjacent to large vessels decreased from the first to the fifth fiber, and from the first to the second fiber adjacent to small vessels. Conversely, tangential fiber diameter increased from the first to the fifth fiber for fibers adjacent to large vessels, and from the first to the second fiber adjacent to small vessels. The fibers adjacent to the vessel seem to have thicker walls in both the tangential than radial directions up to 2 and 5 fibers for small and large vessels, respectively. The first two fibers adjacent to small diameter vessels may produce higher strength paper than those up to five fibers from large diameter vessels, because the Runkel ratio, Coefficient of rigidity and Muhlsteph ratio values of fibers adjacent to small vessels are lower than fibers adjacent to large vessels. The opposite occurs for flexibility coefficient values.

Numerical and Experimental Study on Sheet Hydroforming of 2A12 Aluminum Alloy

2016 ◽  
Vol 716 ◽  
pp. 981-987
Author(s):  
Chu Wang ◽  
Min Wan ◽  
Wen Nan Yuan
Keyword(s):  
Aluminum Alloy ◽  
Wall Thickness ◽  
Initial Pressure ◽  
Pressure Curve ◽  
Cavity Pressure ◽  
Sheet Hydroforming ◽  
Fundamental Parameters ◽  
Sheet Formability ◽  
Hydroforming Process

In this paper, the sheet hydroforming process of 2A12 aluminum alloy with uniform die cavity pressure on to the blank is proposed and investigated both primarily through the finite element method (FEM) and experiments. The influence of the die cavity pressure curve on the quality of the products was explored and the measures to promote the sheet formability were discussed. The results from the studied case indicate that the profile of the cavity pressure was one of the fundamental parameters directly related to the product's quality and precision. Excessive or insufficient initial pressure is not conducive for the reduction of wall thickness thinning and guarantee of wall thickness uniformity. And the wall thickness thinning is reduced and the thickness evenness is improved by increasing the maximum cavity pressure within a proper range. Moreover, an optimum cavity pressure curve generated by the numerical and experimental methods was properly applied in forming the aluminum alloy part without rupture and with slight wrinkle in the flange area. The study demonstrates that the results of simulations based on the identified parameters were in reasonable agreement with those from experiments.

Fatigue Design Criteria for Small Super Duplex Steel Pipes

2004 ◽  
Author(s):  
Steinar Kristoffersen ◽  
Per J. Haagensen
Keyword(s):  
Stainless Steel ◽  
Wall Thickness ◽  
Large Diameter ◽  
Small Diameter ◽  
High Strength ◽  
Gas Production ◽  
Steel Pipes ◽  
Fatigue Design ◽  
Duplex Steel ◽  
Design Guidance

Stainless steel pipes ranging in sizes from approximately 10 to 100 mm OD are used extensively in umbilicals for the control and monitoring of underwater installations for oil and gas production. Umbilicals are subjected to tensile loads as well as variable amplitude loading from wave and current actions. Fatigue is therefore a critical issue in the design of umbilical components. Sea water resistant high strength super duplex steel with ultimate strength of typically 800 to 900 MPa is used to save weight and reduce the wall thickness. Some umbilicals installed by Statoil have design pressure up to 1035 bar, which in combination with large dynamic loads from floating production units makes fatigue design of the umbilicals a challenging issue. While the fatigue performance of butt welded pipes for pipelines and risers are established and implemented in design guidance and codes, the experimental basis for design of small diameter piping made of high strength materials is not well documented in the open literature. However, unpublished data from in-house investigations indicate that small pipes in super duplex steel perform significantly better than larger diameter pipes in lower strength materials. It is therefore apparently scope for a “thinness effect”, i.e. a bonus effect that could be applied to the data for large diameter pipes in current codes to account for the higher S-N curves for small stainless steel pipes. This paper reviews some of the fatigue data for piping and compares these data with experimental evidence from a joint industry project. Tentative fatigue design guidance for small diameter super duplex steel piping is presented. Questions concerning special issues such as the possible influence of wall thickness, mean stress and pre-straining due to reeling are discussed.

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