A New Method of Producing Bend Angle by Applying Sheet Forging to V-Bending Process

2015 ◽  
Vol 651-653 ◽  
pp. 1066-1071 ◽  
Author(s):  
Takayuki Aso ◽  
Takashi Iizuka ◽  
Tomoyuki Ota
Keyword(s):  
Plastic Deformation ◽  
Sheet Metal ◽  
Final Stage ◽  
Empirical Method ◽  
New Method ◽  
Bend Angle ◽  
Bending Process ◽  
Punch Displacement ◽  
Bend Angles

In actual manufacturing, some empirical method such as the bottoming technique is generally used in order to adjust the bend angles of products. In this study, a new method for controlling the bend angle in the V-bending process was attempted by applying sheet metal forging. In the experiments, three punches with lumps at the punch tip were used. These lumps were pushed into a bent section at the final stage of bending and were able to stretch the inside plane of the bent section. In both cases examined (using punches with one or two lumps at the tip), the bend angle decreased with an increase in punch displacement. This result shows new possibilities for controlling the bend angle by introducing plastic deformation to the bent section.

Effect of Bend Angle on Gross Plastic Deformation of Pipe Bends: A Finite Element Based Study

2015 ◽  
Author(s):  
Anindya Bhattacharya ◽  
Sachin Bapat ◽  
Hardik Patel ◽  
Shailan Patel
Keyword(s):  
Plastic Deformation ◽  
Finite Element ◽  
Failure Mechanisms ◽  
Bending Moment ◽  
Bend Angle ◽  
Piping System ◽  
Plastic Collapse ◽  
Collapse Load ◽  
Pipe Bend ◽  
Bend Angles

Bends are an integral part of a piping system. Because of the ability to ovalize and warp they offer more flexibility when compared to straight pipes. Piping Code ASME B31.3 [1] provides flexibility factors and stress intensification factors for the pipe bends. Like any other piping component, one of the failure mechanisms of a pipe bend is gross plastic deformation. In this paper, plastic collapse load of pipe bends have been analyzed for various bend parameters (bend parameter = tRbrm2) under internal pressure and in-plane bending moment for various bend angles using both small and large deformation theories. FE code ABAQUS version 6.9EF-1 has been used for the analyses.

Enhanced Semi-Analytical Process Simulation of Air Bending

2005 ◽  
Vol 6-8 ◽  
pp. 729-736 ◽  
Author(s):  
N. Ridane ◽  
D. Jaksic ◽  
Matthias Kleiner ◽  
B. Heller
Keyword(s):  
Sheet Metal ◽  
Process Simulation ◽  
Simulation Software ◽  
Thick Sheet ◽  
Process Data ◽  
Air Bending ◽  
Bending Process ◽  
Sheet Metal Bending ◽  
Punch Displacement ◽  
Analytical Approaches

The air bending process is one of the most widely used process for the manufacturing of sheet metal bending parts made of thin as well as of thick sheet metal. Although the air bending process offers a very high production potential due to its great flexibility, it is associated with certain problems which can negatively influence the shape and dimensional accuracy of the bending parts. Examples for such negative influences are the springback of the material, the batch variations, or the deflections of the bending machine and tools. These differences have to be considered either in the determination of the process parameters or they have to be compensated later on in the manufacturing process itself. A well established approach to calculate process data for forming processes is the use of a process simulation. At the Institute of Forming Technology and Lightweight Construction (IUL) a simulation software called Sheet Metal Bending Simulation (SMBS) has been developed and successfully been tested for the field of sheet metal bending, based on semi-analytical approaches. Although it already provides very satisfactory results in general, disturbances such as material and batch variations as well as the deflections of C-frame, machine table, and press brake ram can still negatively affect the prediction of the punch displacement necessary to achieve a certain bend angle. While material and batch variations cannot properly be considered in a process simulation at present, the afore mentioned influences offer a promising potential for improvements. Therefore, in order to further improve the accuracy of predicted quantities such as punch displacement and bending angle, a new module describing the elastic machine behaviour of press brakes has been developed and successfully been integrated in the process simulation SMBS. Experimental investigations have been carried out on a conventional CNC press brake to verify the efficiency of the newly implemented approach.

Springback Compensation by Superposition of Stress in Air Bending

2009 ◽  
Vol 410-411 ◽  
pp. 621-628 ◽  
Author(s):  
Andres Weinrich ◽  
Nooman Ben Khalifa ◽  
Sami Chatti ◽  
Uwe Dirksen ◽  
A. Erman Tekkaya
Keyword(s):  
Sheet Metal ◽  
New Method ◽  
Lightweight Construction ◽  
Springback Compensation ◽  
Air Bending ◽  
Forming Technology ◽  
Bending Process ◽  
The Common ◽  
Metal Processing Industry ◽  
Free Bending

In the sheet metal processing industry bending is one of the common metal forming processes. Depending on the process state, a differentiation has to be made between free bending (air bending) in the die and coining (die bending). Because of its flexibility the air bending process is nowadays one of the widely applied processes for sheet metal bending, but the springback phenomenon is still a great challenge for the industrial application. At the Institute of Forming Technology and Lightweight Construction (IUL) of the Technische Universität Dortmund, Germany, a new method has been developed allowing the compensation of springback effects in air bending of sheet metals. This method is based on the incremental and local superposition of stresses in the forming zone. The superposition occurs after the bending operation but before unloading along the sheet metal width. The advantage of this new method is that a minimal force is required to compensate the springback. This paper describes the springback compensation method in detail and presents first experimental results.

Prediction of springback in wipe-bending process of sheet metal using neural network

2009 ◽  
Vol 30 (2) ◽  
pp. 418-423 ◽  
Author(s):  
Recep Kazan ◽  
Mehmet Fırat ◽  
Aysun Egrisogut Tiryaki
Keyword(s):  
Neural Network ◽  
Sheet Metal ◽  
Bending Process

Effect of structural deformations and bend angle on the collapse load of pipe bends subjected to in-plane closing bending moment

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Silambarasan R. ◽  
Veerappan A.R. ◽  
Shanmugam S.
Keyword(s):  
Plastic Material ◽  
Large Strain ◽  
Bending Moment ◽  
Bend Angle ◽  
Plastic Collapse ◽  
Collapse Load ◽  
Pipe Bend ◽  
Content Type ◽  
Structural Deformations ◽  
Bend Angles

Purpose The purpose of this study is to investigate the effect of structural deformations and bend angle on plastic collapse load of pipe bends under an in-plane closing bending moment (IPCM). A large strain formulation of three-dimensional non-linear finite element analysis was performed using an elastic perfectly plastic material. A unified mathematical solution was proposed to estimate the collapse load of pipe bends subjected to IPCM for the considered range of bend characteristics. Design/methodology/approach ABAQUS was used to create one half of the pipe bend model due to its symmetry on the longitudinal axis. Structural deformations, i.e. ovality (Co) and thinning (Ct) varied from 0% to 20% in 5% steps while the bend angle (ø) varied from 30° to 180° in steps of 30°. Findings The plastic collapse load decreases as the bend angle increase for all pipe bend models. A remarkable effect on the collapse load was observed for bend angles between 30° and 120° beyond which a decline was noticed. Ovality had a significant effect on the collapse load with this effect decreasing as the bend angle increased. The combined effect of thinning and bend angle was minimal for the considered models and the maximum per cent variation in collapse load was 5.76% for small bend angles and bend radius pipe bends and less than 2% for other cases. Originality/value The effect of structural deformations and bend angle on collapse load of pipe bends exposed to IPCM has been not studied in the existing literature.

Research on Cold Orbital Forming of Complex Sheet Metal of Aluminum Alloy

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Xinghui Han ◽  
Qiu Jin ◽  
Lin Hua
Keyword(s):  
Plastic Deformation ◽  
Finite Element ◽  
Aluminum Alloy ◽  
Mobile Phone ◽  
Sheet Metal ◽  
Experimental Results ◽  
Complex Motion ◽  
Flow Lines ◽  
Inner Surface ◽  
Orbital Forming

This study aims at exploring the potentialities of cold orbital forming in forming complex sheet metal. Aiming at a complex mobile phone shell component of aluminum alloy, two technical schemes for cold orbital forming are first presented. Then, the optimized one, i.e., the more complex inner surface of mobile phone shell is arranged to be formed by the rocking punch with a complex motion, is determined by analyzing the nonuniform plastic deformation laws and punch filling behaviors. On the basis of the optimized technical scheme, the blank geometry in cold orbital forming of mobile phone shell is also optimized based on the forming status of the most difficult forming zone. The consistent finite element (FE) simulated and experimental results indicate that under the optimized technical scheme, not only the bosses in the mobile phone shell are fully formed but also the obtained flow lines are reasonable, which proves that the technical scheme presented in this study is feasible and cold orbital forming exhibits huge potentialities in forming complex sheet metal.

Intelligent Control Experiment Study for V-Shape Free Bending of Wide Sheet Metal

2008 ◽  
Vol 575-578 ◽  
pp. 186-191
Author(s):  
Jun Zhao ◽  
Chun Jian Su ◽  
Ying Ping Guan
Keyword(s):  
Sheet Metal ◽  
Intelligent Control ◽  
Control Experiment ◽  
Bending Process ◽  
Prediction And Control ◽  
The Neural Networks ◽  
Die Material ◽  
Object Of Study ◽  
And Control ◽  
Free Bending

The main problem in bending process of sheet metal is that it is difficult to control bending springback accurately. Springback produced from the unloading of bending makes the shape and size incongruent between bending workpiece and working portion of die. Because the final shape of bending workpiece is related with the whole deformation process, the geometric parameter of die, material performance parameter will have great effect on springback. Therefore, the springback problem is very complicated and the prediction and control of springback is the key to improve the accuracy of bending workpiece. Taking the V free bending of wide sheet as an object of study, the neural networks technology and data acquisition system based on LabVIEW are used to establish intelligent control experiment system for V free bending of wide sheet metal. The control accuracy of system is high and it provides the basis for the realization of intelligent control for V-shape free bending of wide sheet metal in practice in future.

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