Theoretical and experimental investigation of shaping process of circular metal tubes into triangular columns by the elastoforming method

2016 ◽  
Vol 231 (4) ◽  
pp. 658-674 ◽  
Author(s):  
Abbas Niknejad ◽  
Seyed Ghaem Amirhosseini ◽  
Nader Setoudeh
Keyword(s):  
Wall Thickness ◽  
Deformation Mode ◽  
Dissipated Energy ◽  
Theoretical Formula ◽  
Forming Process ◽  
Flat Punch ◽  
Manufacturing Method ◽  
Circular Tubes ◽  
Shaping Process ◽  
Different Characteristics

In this article, a new manufacturing method is introduced to shape circular tubes into columns with triangular cross-section by the elastoforming process. Also, a theoretical analysis is performed to derive a theoretical formula for predicting total dissipated energy that is required for the forming process. For this purpose, V-shape dies with different angles are designed and some aluminum and brazen tubes with different characteristics are prepared. The circular tubes in the empty and filled conditions are compressed between a rigid V-shape die and a flat punch, and during the plastic deformation under the lateral loading, the tubes are shaped into the triangular sections. Considering different tube lengths, outer diameters and wall thicknesses, the specimens are categorized. Also, some of the samples are filled by cylindrical polyethylene Teflon with different thicknesses to investigate the effects of Teflon-filler on the shaping process of the triangular columns. The experiments show that using the cylindrical Teflon-filler, deformation mode of the triangular tubes improves, significantly. In addition, experimental observations of the deformation modes illustrate that there is an optimum value for wall thickness of cylindrical Teflon-filler and the tubes with the optimum Teflon-filler forms close to desirable triangular shape. The results show that by increasing tube wall thickness, probability of crack initiation and fracture reduces. Furthermore, comparison of estimations by the presented theory and the corresponding experimental measurements show an acceptable agreement, in both of empty and filled conditions.

scholarly journals Artificial neural network for modeling and investigating the effects of forming tool characteristics on the accuracy and formability of thin aluminum alloy blanks when using SPIF

2021 ◽  
Author(s):  
Sherwan Mohammed Najm ◽  
Imre Paniti
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Process Parameters ◽  
Single Point ◽  
Tool Material ◽  
Deformation Mode ◽  
Geometric Accuracy ◽  
Forming Process ◽  
Tool Shape ◽  
Artificial Neural

AbstractIncremental Sheet Forming (ISF) has attracted attention due to its flexibility as far as its forming process and complexity in the deformation mode are concerned. Single Point Incremental Forming (SPIF) is one of the major types of ISF, which also constitutes the simplest type of ISF. If sufficient quality and accuracy without defects are desired, for the production of an ISF component, optimal parameters of the ISF process should be selected. In order to do that, an initial prediction of formability and geometric accuracy helps researchers select proper parameters when forming components using SPIF. In this process, selected parameters are tool materials and shapes. As evidenced by earlier studies, multiple forming tests with different process parameters have been conducted to experimentally explore such parameters when using SPIF. With regard to the range of these parameters, in the scope of this study, the influence of tool material, tool shape, tool-end corner radius, and tool surface roughness (Ra/Rz) were investigated experimentally on SPIF components: the studied factors include the formability and geometric accuracy of formed parts. In order to produce a well-established study, an appropriate modeling tool was needed. To this end, with the help of adopting the data collected from 108 components formed with the help of SPIF, Artificial Neural Network (ANN) was used to explore and determine proper materials and the geometry of forming tools: thus, ANN was applied to predict the formability and geometric accuracy as output. Process parameters were used as input data for the created ANN relying on actual values obtained from experimental components. In addition, an analytical equation was generated for each output based on the extracted weight and bias of the best network prediction. Compared to the experimental approach, analytical equations enable the researcher to estimate parameter values within a relatively short time and in a practicable way. Also, an estimate of Relative Importance (RI) of SPIF parameters (generated with the help of the partitioning weight method) concerning the expected output is also presented in the study. One of the key findings is that tool characteristics play an essential role in all predictions and fundamentally impact the final products.

scholarly journals Optimization of Superplastic Forming Process of AA7075 Alloy for the Best Wall Thickness Distribution

2021 ◽  
Vol 6 (4) ◽  
pp. 251-261
Author(s):  
Manh Tien Nguyen ◽  
Truong An Nguyen ◽  
Duc Hoan Tran ◽  
Van Thao Le
Keyword(s):  
Wall Thickness ◽  
Deformation Temperature ◽  
Numerical Optimization ◽  
Thickness Distribution ◽  
Superplastic Forming ◽  
Forming Process ◽  
Wall Thickness Distribution ◽  
Surface Method ◽  
Series Of Experiments ◽  
The Relationship

This work aims to optimize the process parameters for improving the wall thickness distribution of the sheet superplastic forming process of AA7075 alloy. The considered factors include forming pressure p (MPa), deformation temperature T (°C), and forming time t (minutes), while the responses are the thinning degree of the wall thickness ε (%) and the relative height of the product h*. First, a series of experiments are conducted in conjunction with response surface method (RSM) to render the relationship between inputs and outputs. Subsequently, an analysis of variance (ANOVA) is conducted to verify the response significance and parameter effects. Finally, a numerical optimization algorithm is used to determine the best forming conditions. The results indicate that the thinning degree of 13.121% is achieved at the forming pressure of 0.7 MPa, the deformation temperature of 500°C, and the forming time of 31 minutes.

Leveling Quality Prediction Algorithm

2015 ◽  
Vol 809-810 ◽  
pp. 235-240
Author(s):  
Catalina Maier ◽  
Robin Gauthier
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Theoretical Model ◽  
Cumulative Effect ◽  
Prediction Algorithm ◽  
Forming Process ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Experimental Values ◽  
Different Characteristics

Roller leveling is a forming process which used to minimize flatness imperfection and residual stresses by repeated forming process of a sheet metal. The determination of the machine settings must be very accurate and ask a precise mechanical study. In order to determine an algorithm which can predict the leveling quality according to the machine settings we start by a theoretical model of stress evolution during the process. The plastification ratio is deducted from this one and the values obtained by this approach are compared whit experimental values. The finite element analysis is performed, in second step in order to assure a good accuracy of the prediction algorithm. Theoretical study determines a minimum of the plastification ratio according to the machine settings. The finite element analysis gives more accurate results due to the consideration of different characteristics of the process, neglected by the theoretical model: cumulative effect of bending/unbending with stretching of the sheet during the passing between each couple of rolls, boundary conditions at the limit of the material deformed by two adjoining couples of rolls, friction force.

scholarly journals Investigation of Slip Occurrence in the Ring Rolling Process

2019 ◽  
Vol 291 ◽  
pp. 02006
Author(s):  
Andrzej Gontarz ◽  
Piotr Surdacki
Keyword(s):  
Wall Thickness ◽  
Failure Modes ◽  
Rolling Process ◽  
Ring Rolling ◽  
Thickness Reduction ◽  
Main Stage ◽  
Forming Process ◽  
Limit Values ◽  
Ring Shape ◽  
Ring Rolling Process

Ring rolling is a hot forming process for producing rings that have large diameters when compared to their cross sections. This process is very dynamic and involves considerable variations in ring shape and size. One of the failure modes in ring rolling processes is slip that occurs when a thickness reduction, exceeds the limit value. The thickness reduction depends on the tool speed and dimensions as well as ring size, and varies over time. This paper reports results of a study investigating the thickness reduction with respect to slip occurrence. In terms of wall thickness reduction, the process can be divided into three distinct stages (excluding the sizing stage): (i) initial stage corresponding to the first revolution of the roll, (ii) main stage, when the proper ring rolling takes place, (iii) final stage, when the main roll does not move in an axial direction but the ring is being formed during one revolution of the tool. It has been found that the most slip-prone moment is the end of the second and the beginning of the third stage of the ring rolling process, when the wall thickness reduction is the highest. Based on a comparison of the calculated thickness reduction and its limit values, it could be predicted whether slip would occur, and if so – in what stage of the rolling process. Numerical results and experimental findings are in good agreement.

scholarly journals New Numerical Model of Composite Fabric Behaviour: Simulation of Manufacturing of thin Composite Part

2000 ◽  
Vol 9 (3) ◽  
pp. 096369350000900 ◽  
Author(s):  
J.L. Billoet ◽  
A. Cherouat
Keyword(s):  
Mechanical Properties ◽  
Tensile Tests ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Forming Process ◽  
Composite Part ◽  
Initial Shape ◽  
Shaping Process ◽  
Mechanical Approach ◽  
Behaviour Simulation

The present study concerns the modelling of the behaviour of pre-impregnated woven fabric during the forming process. The mechanical approach is based on a mesostructural model. It allows us to take into account the mechanical properties of fibres and resin and the various dominating mode of deformation of woven fabrics during the forming process. Shear and tensile tests of composite fabric specimens are proposed and compared with the experimental results in order to demonstrate the efficiency of our approach. Different numerical simulations and experiments of shaping process have been carried out in order to validate the proposed computational formulation. The various forming parameters examined have included the initial shape of fabric, fibre orientations and viscosity of resin.

Computer Simulation of Filling Process and Temperature Distribution of Oil Pump Cover in Solidification Process

2013 ◽  
Vol 423-426 ◽  
pp. 1894-1897
Author(s):  
Han Wu Liu ◽  
Lian Dong Huang ◽  
Shun Qin Fan ◽  
Bo Hu
Keyword(s):  
Wall Thickness ◽  
Thermal Equilibrium ◽  
Cooling System ◽  
Die Casting ◽  
Solidification Process ◽  
Equilibrium Temperature ◽  
Forming Process ◽  
Element Analysis ◽  
Casting Mold ◽  
Oil Pump

Oil pump cover, as a part of the oil pump, is generally formed by adopting aluminum die casting molding, and required for good internal and external quality. In order to improve the oil pump cover forming quality, the paper first simulates the thermal equilibrium of die-casting mold in the forming process by finite element analysis, and obtains the temperature curves when mold works for 10 consecutive cycles, and determines that the thermal equilibrium temperature of die-casting mold is 260 °C. And then, based on the simulation results of filling and solidification in the forming process by ProCAST software, the shrinkage and cavity appear in the larger wall thickness of the casting. Meanwhile, by simulating the die-casting processes of the oil pump at different pouring temperatures, there are the least of shrinkage and cavity when the pouring temperature setting 640 °C. The results show that: it can take some methods to achieve the progressive solidification, and can reduce or eliminate the possible shrinkage and cavity, such as shortening the distance between sprue, runner and inner runner and die casting to reduce the casting heat loss, or adding cooling system to accelerate the cooling rate in the larger wall thickness of the casting. This analysis provides theoretical basis for the actual casting production of oil pump covers.

Development of Manufacturing Method for Truss Core Panel Based on Origami-Forming

2015 ◽  
Author(s):  
Hoan Thai Tat Nguyen ◽  
Phuong Thao Thai ◽  
Bo Yu ◽  
Ichiro Hagiwara
Keyword(s):  
Forming Process ◽  
Robot System ◽  
Cutting Method ◽  
Manufacturing Method ◽  
Truss Core ◽  
Equivalent Bending Stiffness ◽  
Lightweight Structure ◽  
Partition Method ◽  
In Fire ◽  
Honeycomb Panel

Although honeycomb panel is widely used in various stages, its adhesive for gluing honeycomb core and plate may burn by fire, leading to the requirement of another lightweight and high stiffness panel. Recently, an Origami structure called Truss Core Panel (TCP) is known as a lightweight structure that has equivalent bending stiffness as honeycomb panel, and safer in fire. However, some difficulties are found in forming TCP in general. In this study, a new forming process of TCP based on origami-forming is developed. In particular, the TCP is partitioned into several parts that are flat unfoldable into 2D crease patterns. After that, blanks of material are cut as the shapes of those crease pattern, and be formed by a robot system to get the desired 3D shape. Firstly, partition method by dividing TCP into pyramid cores and sheet plate is presented, suggesting an ability to manufacture a wider range of structure than before. Tools arrangement of robot device and a countermeasure for springback are considered. Next, by applying Origami unfolding technique, an improvement of partition method is proposed: dividing TCP into cores rows, and then searching for a Origami crease pattern in order to fold that cores row. The cutting method of every core is modified for reducing the number of facets, making the problem simpler. Finally, an Origami crease pattern based on this new cutting method is presented, producing cores row with any number of cores.

Effects of Hydroforming Process on Fatigue Life of Reinforced S-Shaped Bellows

2019 ◽  
Vol 795 ◽  
pp. 296-303
Author(s):  
Zhe Yuan ◽  
Shi Hui Huo ◽  
Jian Ting Ren
Keyword(s):  
Plastic Deformation ◽  
Fatigue Life ◽  
Plastic Strain ◽  
Wall Thickness ◽  
Mechanical Characteristics ◽  
Forming Process ◽  
Weak Part ◽  
Metal Bellows ◽  
Hydroforming Process ◽  
Fatigue Life Analysis

Reinforced s-shaped bellows, which can withstand high pressure, is a kind of typical reinforced metal bellows. The reinforced s-shaped bellows mainly uses the hydroforming process, and the forming process is a severe plastic deformation process. The hydroforming process and its effects on the fatigue life of reinforced s-shaped bellows were discussed in the present study. Different levels of plastic strain and wall thickness thinning were detected in the hydroforming process. The maximum plastic strain can reached 32%, while the maximum wall thickness thinning ratio is 20%, which occurs on the wave peak. Mechanical characteristics of reinforced s-shaped bellows were discussed considering the effects of hydroforming process. The maximum stress appears on the upper and lower ends, which is the weak part of the structure. Fatigue life of the reinforced s-shaped bellows was analyzed based on the modified Manson-Coffin method. Mechanical properties of related materials, which can be more accurate consideration the effects of hydroforming process, were tested under the pre-plastic deformation. Fatigue life analysis of reinforced s-shaped bellows was carried out and the effects of hydroforming process were discussed. The hydroforming process will lead to a decline in fatigue life, which needs to be considered well in the structural design and analysis. Keywords: Reinforced s-shaped bellows, Hydroforming process, Fatigue life, Mechanical characteristics.

Effect of Compressive and Shear Deformation of 2.5D Preform on its Stiffness of Composites

2019 ◽  
Vol 943 ◽  
pp. 75-80
Author(s):  
Fang Bin Lin ◽  
Ying Dai ◽  
Han Yang Li ◽  
Yang Qu ◽  
Wen Xiao Li
Keyword(s):  
Finite Element ◽  
Shear Deformation ◽  
Cell Model ◽  
Deformation Mode ◽  
Element Model ◽  
Tensile Tests ◽  
Woven Composites ◽  
Forming Process ◽  
Element Analysis ◽  
Plane Shear

Transverse compaction and in-plane shear deformartion are the dominative deformation mode for woven preform during forming process. A full finite element model of the 2.5D woven composites has been established by the computed tomography (CT) in this paper. Based on the energy method, the effective orthotropic/anisotropic stiffness coefficientsCijare calculated by performing a finite element analysis (FEA) of this full cell model. Using this model, the effects of the compaction and shear deformation of the 2.5D woven preform on the composites stiffness are investigated in detail. Compared the results of the static tensile tests, the rationality of the model and the method is verified.

FEM analysis of pipe reduction forming process for increasing of wall thickness

PRICM ◽  
2013 ◽  
pp. 2503-2507
Author(s):  
Daisuke Kawabata ◽  
Hirotaka Kamiyama ◽  
Shinichi Nishida ◽  
Hisaki Watari
Keyword(s):  
Wall Thickness ◽  
Fem Analysis ◽  
Forming Process
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