Aluminium Extrusion Weld Formation and Metal Flow Analysis in Hollow Profile Extrusions of Different Section Thickness

2011 ◽  
Vol 491 ◽  
pp. 105-112 ◽  
Author(s):  
Yawar Abbas Khan ◽  
Henry Sigvart Valberg
Keyword(s):  
Wall Thickness ◽  
Perfect Match ◽  
Metal Flow ◽  
Extrusion Process ◽  
Experimental Results ◽  
Fe Model ◽  
Grid Pattern ◽  
Element Analysis ◽  
Weld Formation ◽  
Flow Through

Hollow and semi-hollow profiles are commonly produced by extrusion using porthole dies. The main characteristics of such dies are the presence of a mandrel (core) to shape the inner contour of hollow profile and bridges or legs to carry the mandrel. The bridges split the billet material into multiple metal streams that flow through the porthole channels and meet in the welding chamber behind the bridge where they are joined by pressure welding. When hollow profiles with different wall thickness are made the size of two adjacent portholes may be different. The material then flows through the two portholes with different flow velocity so that there is more feed through the bigger porthole into the weld chamber behind the bridge. Experiments have been performed and are reported here in which a grid pattern technique was used to characterize the metal flow through a 2D-die with porthole channels of unequal size. The design of the laboratory die has been modified in relation to the symmetric case to get different sizes of the two portholes. Since the metal flow through such a die is asymmetric the grid pattern technique was also modified to characterize the experimental flow. The results of an experimental metal flow study performed for a short billet was presented in a previous article [1]. Corresponding experiments performed with longer billets are now reported; so that two stages of the extrusion process is analysed here. The grid pattern technique has successfully mapped the non-symmetric material flow as in industrial extrusion when using different wall thickness over the section. The lateral movement of metal during extrusion is obtained from one set of experiments; the vertical movement from the other set. Finite element analysis of the extrusion process has been performed using Deform 3D. The encountering of the two metal streams behind the die bridge and the deformation characteristics within the welding chamber has been studied this way. Extrusion weld formation and deformations around the die bridge are considered here with the help of experimental results and simulation models. The nature of the metal flow achieved from the FE-model is compared with the experimental results. As regards the short billet some results are presented in [1], however improvement to the previous model gives a more perfect match. The model also provides information about the boundary conditions in real extrusion.

Analysis of Metal Flow of Aluminum through Long Choked Die Channels

2009 ◽  
Vol 424 ◽  
pp. 145-152 ◽  
Author(s):  
Henry Sigvart Valberg
Keyword(s):  
Cross Section ◽  
Channel Wall ◽  
Metal Flow ◽  
Extrusion Process ◽  
Sliding Contact ◽  
Aluminum Extrusion ◽  
Grid Pattern ◽  
Contact Conditions ◽  
New Knowledge ◽  
Flow Through

The mechanics of metal flow through long choked die channels have been investigated in unlubricated hot aluminum extrusion. Experiments were performed in a laboratory press at an earlier occasion by letting a grid pattern introduced into the billet flow down into the choked die channel to appear adjacent to the channel wall. The grid pattern was then revealed to characterize the metal flow in the channel. A 2D-model of the extrusion process was made. The model was applied to study the conditions in the extrusion experiments and in this model good similarity was obtained with the experiment. New knowledge regarding the metal flow through a choked die channel have been obtained this way, such as; contact conditions, presence of sticking and sliding zones, friction conditions in the sliding contact zone and the velocity profile over the cross-section of the channel.

Finite Element Analysis of Metal Flow of Finishing Groove in Hot Continuous Rolling Bar

2012 ◽  
Vol 510 ◽  
pp. 667-672
Author(s):  
Jia Lin Zhou ◽  
Chen Gang Pan ◽  
Xiao Yong Zhang
Keyword(s):  
Strain Distribution ◽  
Metal Flow ◽  
Dimensional Accuracy ◽  
Stress And Strain ◽  
Fe Model ◽  
Element Analysis ◽  
Iron And Steel ◽  
Expansion Angle ◽  
The Stability ◽  
Stress And Strain Distribution

This article established 3D FE model of dual-radius arc finishing groove and tangent expansion angle finishing groove using ANSYS / LS-DYNA software for Wuhan Iron and Steel plant Ф16 hot continuous bar, and analyzed metal flow pattern, stress and strain distribution of two types finishing grooves. The results show that surface stress and strain distribution of dual-radius arc finishing groove have better uniform than them of tangent expansion angle finishing groove, and dual-radius arc finishing groove ensures the stability of the rolled piece in finishing groove, improve the dimensional accuracy and surface quality of rolled finishing product.

Parallel Extrusion of Aluminum Alloy Heat Sink with Round-Fin

2013 ◽  
Vol 739 ◽  
pp. 131-135
Author(s):  
Li Han Zhang ◽  
Ke Sheng Wang ◽  
Yu Han ◽  
Jia Yu Ying
Keyword(s):  
Heat Sink ◽  
Material Flow ◽  
Extrusion Process ◽  
Element Analysis ◽  
Automotive Lighting ◽  
Metal Sheets ◽  
The Finite Element Analysis ◽  
Alloy Heat ◽  
Flow Through ◽  
Good Agreement

Parallel extrusion is a combined extrusion process for forming round-fin heat sink on thick metal sheets. In this paper, the parallel extrusion has been applied to manufacture the round-fin heat sink in the automotive lighting. Numerical simulations on the round-fin heat sink forming using the software DEFORM were carried out. The tooling structure with counterpressure on the heat sink formation was investigated. The results show that the tooling structure with counterpressure is helpful to the formation of round-fin heat sink, which not only ensures the height of each round-fin on the heat sink is uniform but also retards the initiation of flow-through on the reverse side of round-fin. In addition, the experiments of press forging process were conducted to validate the finite element analysis, it is shown that the friction at the punch-blank interface has more significant effect on preventing the initiation of flow-through compared with the friction at the die-blank interface, which implies that the punch-blank interface has more significant effect on the material flow in the formation of round-fin, and the simulation results are in good agreement with the experimental data.

Experimental and finite element study on the single-layer reticulated composite joints

2020 ◽  
Vol 23 (10) ◽  
pp. 2174-2187
Author(s):  
Liang Zheng ◽  
Cheng Qin ◽  
Hong Guo ◽  
Dapeng Zhang ◽  
Mingtan Zhou ◽  
...  
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Axial Compression ◽  
Wall Thickness ◽  
Great Influence ◽  
Single Layer ◽  
Experimental Results ◽  
Steel Pipe ◽  
Cover Plate ◽  
Element Analysis

In this article, a new type of reticulated joint, named the steel–concrete composite reticulated shell joint, is proposed. The proposed reticulated shell joint consists of an inner circular steel pipe, an outer circular steel pipe, a steel cover plate, and internal concrete. Five test specimens were tested under axial compression. The variable study included the wall thickness of the inner and outer circular steel pipes and the radius of the inner circular steel pipe. The test specimens exhibited a high bearing capacity and good plastic deformation ability under axial compression. The test results show that the wall thickness of the outer circular steel pipe and the radius of the inner circular steel pipe have a great influence on the bearing capacity of the steel–concrete composite reticulated shell joint, while the wall thickness of the inner circular steel pipe has little influence on the bearing capacity of the steel–concrete composite reticulated shell joint. Based on the test of the steel–concrete composite reticulated shell joints under axial load, the three-dimensional nonlinear finite element model was used to analyze the mechanical properties of the steel–concrete composite reticulated shell joints under axial compression. The results of the finite element analysis showed good agreement with the experimental results. The formula for calculating the bearing capacity of the joint is derived. By comparing with the experimental results, the calculated results are basically consistent with the experimental results.

A study on finite element analysis for simplification of curvature extrusion method

2018 ◽  
Vol 32 (19) ◽  
pp. 1840043
Author(s):  
J. O. Yu ◽  
Y. H. Kim ◽  
Nagamachi Takuo
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Friction Coefficient ◽  
Extrusion Process ◽  
Experimental Results ◽  
Element Analysis ◽  
Extrusion Method ◽  
Good Agreement

To eliminate the complexity of curvature extrusion process, a new extrusion method was proposed. In this study, a finite element analysis for curvature extrusion was studied to commercialize this extrusion method that creates curvature in a tilting method. When simulating an extrusion process, it is important to fix the appropriate friction coefficient and fillet value to avoid peel-out problems such that the finite element disappears. Therefore, the actual extrusion results and the simulated results were compared to find conditions that the element would not disappear. There was a good agreement between the simulation and experimental results when the coefficient friction was 0.4 and the fillet was 0.4 mm.

Metal Flow in Two-Hole Extrusion of Al-Alloys Studied by FEA with Experiments

2012 ◽  
Vol 504-506 ◽  
pp. 493-498 ◽  
Author(s):  
Janis Kandis ◽  
Henry Valberg
Keyword(s):  
Metal Flow ◽  
Shear Zones ◽  
Grid Pattern ◽  
Experimental Conditions ◽  
Element Analysis ◽  
Flow Phenomena ◽  
Long Time ◽  
Billet Material ◽  
Deform 3D ◽  
Insight Into

Forward two-hole extrusion of Al has been investigated with the purpose of studying how metal flow inside the billet is influenced by the location of the holes in the dies, i.e. whether they are position near to or far apart from each other. The study has been conducted by means of finite element analysis (FEA) using the software DEFORM 3D® and validation of simulation results are done by comparison with grid pattern experiments performed long time ago by one of the authors. The analysis shows that the experimental conditions are well reproduced by FEA. New insight into the metal flow phenomena in two-hole extrusion is also gained thanks to the analysis. It is shown, for instance, that moving the holes far apart from each other brings about a distinct shift in the metal flow. The deformations subjected to the peripheral outer shear zones of the billet material then become much more localized than when the two holes are close.

Deformations in Idealized 2D Extrusion Welding

2013 ◽  
Vol 554-557 ◽  
pp. 2507-2522 ◽  
Author(s):  
Henry Valberg ◽  
Dirk Nolte ◽  
Sepinood Torabzadeh Khorasani
Keyword(s):  
Strain Distribution ◽  
Dead Zone ◽  
Effective Strain ◽  
Metal Flow ◽  
Extrusion Process ◽  
Experimental Information ◽  
Grid Pattern ◽  
Seam Weld ◽  
Extrusion Welding ◽  
Material Points

Metal flow inside the container and in the metal behind a butt-ended die bridge in idealized aluminum extrusion welding has been investigated by FEA and experiment with respect to the deformation of the material flowing around the bridge and into the layers close the extrusion seam weld. Along the mid-axis of the extrusion process the effective strain subjected to the extrusion material can be determined in three different ways. One way is to determine the strains from grid pattern experiments that reveal the real deformations. When it comes to FEA there are two options; the strains can be determined from the initial and final positions of a number of material points distributed along the mid-axis of the material, where after traditional theoretical strain-equations can be used to calculate the effective strain distribution along the axis. Another possibility is to use the post-processor of the software to calculate the strain distribution. In this work the effective strain distribution along the mid-axis of the billet inside the container volume were determined by all these three methods. The effective strain in the thin layer of the squeeze zone ahead of the dead zone in front of the die bridge determined from the experiments was found to be much larger than the strains elsewhere along this axis. The same was the case when effective strain was determined by FEA from the computed position of the points, but this strain value was predicted approximately 10% lower than the corresponding value from the experiments in the layer with the heaviest strains. However, when this effective strain distribution was calculated by the post-processor of the software the high-strain layer in the squeeze zone was not revealed at all, instead the effective strains were predicted rather even over the whole length of the mid-axis. Corresponding effective strain distributions were determined along the mid-axis of the extrusion material in the weld chamber also, and after outflow of this material into the extrusion seam weld of the resulting profile where no experimental information is available. When this effective strain distribution was computed by FEA, based on initial and final position of points, very different strain values were obtained as compared to when same strains were collected directly from the post-processor. It is believed that the first results, i.e., the effective strains computed from the points are quite accurate, while those values calculated by the post-processor are less reliable.

On the Balance of the Metal Flow in Porthole Dies with Differently Sized Porthole Channels

2013 ◽  
Vol 585 ◽  
pp. 77-84 ◽  
Author(s):  
Henry Sigvart Valberg ◽  
Dirk Nolte ◽  
Yawar Abbas Khan
Keyword(s):  
Metal Flow ◽  
Fe Analysis ◽  
Grid Pattern ◽  
Fem Model ◽  
Unequal Size ◽  
Flow Through

The relative balance between the metal flow in two portholes in extrusion has been investigated by experiments and FE-analysis. The investigation deals with asymmetric extrusion, i.e., the billet is extruded through a die with portholes of unequal size. Metal flow has been characterized by an experimental grid pattern technique. An optimized FEM-model of the experiment has been built and the experimental metal flow is found to be mimicked accurately by this model. The velocity conditions in the two differently sized ports feeding material into the weld chamber, and further from here into the extrudate, have been investigated to see if the balance between the flow through the two channels changes as extrusion proceeds. Increasing asymmetri between the two portholes has been realized in the analysis by displacement of the die bridge laterally in relation to the direction of extrusion.

Metal Flow Conditions in Porthole Channels of Different Size

2014 ◽  
Vol 611-612 ◽  
pp. 1005-1012
Author(s):  
Henry Valberg ◽  
Dirk Nolte ◽  
Khan Yawar
Keyword(s):  
Metal Flow ◽  
Size Difference ◽  
Flow Conditions ◽  
Element Analysis ◽  
Flow Balance ◽  
Porthole Die ◽  
Small Channel ◽  
Flow Through ◽  
Ram Speed ◽  
End Stage

Finite element analysis (FEA) is applied to study metal flow in an asymmetric porthole die with two ports where one port is bigger than the other. It is shown how FEA predicts the velocity differences between the two ports to depend on applied extrusion velocity, i.e., the ram speed, and in addition, how increasing size difference between the ports changes the flow balance between the ports. Two of the simulations have been validated by experiments in previous work, so the trends shown by FEA have also been confirmed experimentally. In long billet extrusion metal flow through the two die channels is predicted stable throughout the major part of the extrusion stroke. However, in the end stage of the process, there is predicted a shift in metal flow. Now the velocity in the small channel is speeded up on the expense of that in the big channel. In short billet extrusion the same shift in metal flow is also confirmed towards end of extrusion. An explanation is given why the metal flow in the small channel speeds up towards end of extrusion. In the article it is also quantified (in a diagram) how big the shift in flow balance between the two ports is as the size difference between the ports increases.

scholarly journals Non-Linear Finite Element Analysis of RC Deep Beam Using CDP Model

2020 ◽  
Author(s):  
Pramod Rai
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Research Work ◽  
Nonlinear Behavior ◽  
Shear Capacity ◽  
Experimental Results ◽  
Modeling Technique ◽  
Fe Model ◽  
Deep Beam ◽  
Element Analysis

Finite element analysis (FEA) is widely adopted these days to investigate relatively heavy structures such as reinforced concrete (RC) deep beam, which requires a higher investment of resources. This research aims to investigate a numerical modeling technique applicable to study the nonlinear behavior of RC deep beams by using FEA based on the software, ABAQUS. The nonlinear behavior of an RC deep beam adapted from an earlier research work is captured by using the uniaxial compressive and tensile stress-strain relationship and damage parameters of concrete. The response of the FE model is verified with the experimental results in terms of the load to midspan deflection curve and damage distribution. The ultimate shear capacity predicted by the FE model is 0.75% lower, and the corresponding displacement is 6.92% higher than the experimental results. The adopted modeling technique and the constitutive concrete models demonstrate the promising results indicating its possibilities for the investigation of RC structures.

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