scholarly journals Study on the Iterative Compensation Method for Continuous Varying Curvature Free Bending

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Ruixue Zhai ◽  
Pengcheng Fu ◽  
Rui Ma ◽  
Jun Zhao ◽  
Cuiyun Ge
Keyword(s):  
Industrial Applications ◽  
Compensation Method ◽  
304 Stainless Steel ◽  
Compensation Mechanism ◽  
Forming Process ◽  
Forming Simulation ◽  
Finite Element Software ◽  
Bending Process ◽  
Continuous Curvature ◽  
Free Bending

The parts formed by the bending process not only have high precision of appearance dimension but also have good performance. In recent years, enterprises have put forward higher requirements for the forming process and product quality. Therefore, a new method for iterative compensation of bending springback with certain generality is proposed for continuous curvature bending. The purpose of this study is to take curvature as an iterative parameter and make the shape size reach the expected value through the finite compensation. On the basis of establishing this iterative compensation mechanism, the convergence of curvature iteration in the general free bending process is proved. The reliability of the proposed iterative compensation method in the bending process engineering application is verified by combining simulation with experiment. The two materials of 304 stainless steel and ST12 cold rolled steel were studied, and the two-dimensional plane stress-strain model Abaqus cantilever beam was established by using finite element software. The bending forming simulation was carried out based on the above iterative compensation mechanism. Finally, through the bending experiments of four models, the feasibility of the iterative compensation mechanism of curvature in the continuous curvature plane bending process is verified, and different models are selected to clarify that the method has the characteristics of generality, that is, it will greatly improve the flexibility of the bending process in industrial applications without the limitation of material types and mechanical models.

The Forming Process of the Sharply Curved Offsets by the Pushing Method

2016 ◽  
Vol 684 ◽  
pp. 242-252
Author(s):  
Valentin Dmitrievich Maslov ◽  
I.P. Popov ◽  
Valentin Dmitrievich Misyura
Keyword(s):  
Thickness Distribution ◽  
Steel Tube ◽  
304 Stainless Steel ◽  
Stainless Steel Tube ◽  
Curvature Radius ◽  
Distribution Law ◽  
Forming Process ◽  
Program Complex ◽  
Bending Process ◽  
Parts Manufacturing

The scheme of device for the thin-walled sharply curved offset parts forming by pushing the tube-shaped workpiece through the die channel is presented. The numerical simulation of the bending process by pushing the tube-shaped workpiece is performed using ANSYS-LS/DYNA program complex. The wall thickness distribution law along the generatrix of curved workpiece is determined. The influence of curvature radius of the curved offset part on thinning deformation during bending process is defined. The experimental determination of the AISI 304 stainless steel tube-shaped workpiece thickness changes is performed. Application of the developed device for the sharply curved offset parts manufacturing according to DIN/ISO standards is demonstrated.

Free-bending process characteristics and forming process design of copper tubular components

2018 ◽  
Vol 96 (9-12) ◽  
pp. 3585-3601 ◽  
Author(s):  
Xunzhong Guo ◽  
Hao Xiong ◽  
Yong Xu ◽  
Yannan Ma ◽  
Ali Abd El-Aty ◽  
...  
Keyword(s):  
Process Design ◽  
Forming Process ◽  
Process Characteristics ◽  
Bending Process ◽  
Free Bending ◽  
Tubular Components

scholarly journals Statistical analysis of the reproducibility of residual stress measurements in cold extruded parts

2021 ◽  
Author(s):  
Fabian Jaeger ◽  
Alessandro Franceschi ◽  
Holger Hoche ◽  
Peter Groche ◽  
Matthias Oechsner
Keyword(s):  
Residual Stress ◽  
Statistical Analysis ◽  
Stress Measurement ◽  
Industrial Applications ◽  
Cold Extrusion ◽  
X Ray Diffraction ◽  
Forming Process ◽  
X Ray ◽  
Stress States ◽  
Key Aspects

AbstractCold extruded components are characterized by residual stresses, which originate from the experienced manufacturing process. For industrial applications, reproducibility and homogeneity of the final components are key aspects for an optimized quality control. Although striving to obtain identical deformation and surface conditions, fluctuation in the manufacturing parameters and contact shear conditions during the forming process may lead to variations of the spatial residual stress distribution in the final product. This could lead to a dependency of the residual stress measurement results on the relative axial and circumferential position on the sample. An attempt to examine this problem is made by the employment of design of experiments (DoE) methods. A statistical analysis of the residual stress results generated through X-Ray diffraction is performed. Additionally, the ability of cold extrusion processes to generate uniform stress states is analyzed on specimens of austenitic stainless steel 1.4404 and possible correlations with the pre-deformed condition are statistically examined. Moreover, the influence of the coating, consisting of oxalate and a MoS2 based lubricant, on the X-Ray diffraction measurements of the surface is investigated.

Analysis on Temperature Field of Work-Piece during Cross Wedge Rolling

2011 ◽  
Vol 230-232 ◽  
pp. 352-356
Author(s):  
Wen Ke Liu ◽  
Kang Sheng Zhang ◽  
Zheng Huan Hu
Keyword(s):  
Finite Element ◽  
Temperature Field ◽  
Metal Flow ◽  
Work Piece ◽  
Contact Deformation ◽  
Cross Wedge Rolling ◽  
Forming Process ◽  
Rigid Plastic ◽  
Finite Element Software ◽  
Deform 3D

Based on the rigid-plastic deformation finite element method and the heat transfer theories, the forming process of cross wedge rolling was simulated with the finite element software DEFORM-3D. The temperature field of the rolled piece during the forming process was analyzed. The results show that the temperature gradient in the outer of the work-piece is sometimes very large and temperature near the contact deformation zone is the lowest while temperature near the center of the rolled-piece keeps relatively stable and even rises slightly. Research results provide a basis for further study on metal flow and accurate shaping of work-piece during cross wedge rolling.

Experimental Assessment of High Temperature Formability of Boron Steel Sheet Manufactured With a Spring Compound Bending Die

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
Yang Li ◽  
Yong-Phil Jeon ◽  
Chung-Gil Kang
Keyword(s):  
Mechanical Properties ◽  
Heating Temperature ◽  
Boron Steel ◽  
Hot Press ◽  
Forming Process ◽  
Steel Sheets ◽  
Press Forming ◽  
Bending Process ◽  
Tension Testing ◽  
Hot Press Forming

Bending behavior occurs in the hot press forming process, resulting in many cases of failure during forming. To address the problem of cracking and improve the formability and mechanical properties of boron steel sheets in the bending process, an experiment has been carried out by using a spring compound bending die. Also, a comparison has been made between the traditional U-bending die and the spring compound bending die with regard to formability. The influence of the parameters for hot press forming such as the heating temperature, punch speed, and die radii on the mechanical properties and microstructure was analyzed by tension testing and metallographic observations.

Topology Optimization of Blank Geometry for the Sheet Forming Process

2012 ◽  
Author(s):  
Saber DorMohammadi ◽  
Mohammad Rouhi ◽  
Masoud Rais-Rohani
Keyword(s):  
Topology Optimization ◽  
Volume Fraction ◽  
Structural Response ◽  
Sheet Forming ◽  
Forming Process ◽  
Exchange Method ◽  
Forming Simulation ◽  
Blank Shape Optimization ◽  
Blank Shape ◽  
Consistent Subset

The newly developed element exchange method (EEM) for topology optimization is applied to the problem of blank shape optimization for the sheet-forming process. EEM uses a series of stochastic operations guided by the structural response of the model to switch solid and void elements in a given domain to minimize the objective function while maintaining the specified volume fraction. In application of EEM to blank optimization, a sheet forming simulation model is developed using Abaqus/Explicit. With the goal of minimizing the variability in wall thickness of the formed component, a subset of solid (i.e., high density) elements with the highest increase in thickness is exchanged with a consistent subset of void (i.e., low density) elements having the highest decrease in thickness so that the volume fraction remains constant. The EEM operations coupled with finite element simulations are repeated until the optimum blank geometry (i.e., boundary and initial thickness) is found. The developed numerical framework is applied to blank optimization of a benchmark problem. The results show that EEM is successful in generating the optimum blank geometry efficiently and accurately.

Investigation on the influence of mandrel on the forming quality of thin-walled tube during free bending process

2021 ◽  
Vol 72 ◽  
pp. 215-226
Author(s):  
Cheng Cheng ◽  
Hao Chen ◽  
Jiaxin Guo ◽  
Xunzhong Guo ◽  
Yuanji Shi
Keyword(s):  
Forming Quality ◽  
Bending Process ◽  
Thin Walled Tube ◽  
Thin Walled ◽  
Free Bending

A Novel Incremental Sheet Bending Process of Complex Curved Steel Plate

2017 ◽  
Vol 139 (11) ◽  
Author(s):  
Qiyang Zuo ◽  
Kai He ◽  
Xiaobing Dang ◽  
Wei Feng ◽  
Ruxu Du
Keyword(s):  
Tool Path ◽  
Numerical Control ◽  
Steel Plates ◽  
Work Piece ◽  
Forming Process ◽  
Shipbuilding Industry ◽  
Supporting System ◽  
Motion Modes ◽  
Bending Process ◽  
Curved Steel

Bending complex curved steel plates for constructing ship hull has long been a challenge in shipbuilding industry. This paper presents a novel incremental bending process to obtain complicated curved steel plates by a series of sequential and layered punches. Taking advantage of this process, the blank plate that is fixed and held by a flexible supporting system can incrementally be bent into the target shape by a press tool along a planned tool path step by step and layer by layer. Acting as a “lower die,” the flexible supporting system can provide flexible and multifunctional supports for the work piece during the forming process, whose four general motion modes are demonstrated in this paper. Meanwhile, the procedures of tool path planning and forming layering are also explained in detail. In addition, aiming at different motion modes of the flexible supporting system, two springback compensation methods are given. Furthermore, according to the forming principle presented in this paper, an original incremental prototype equipment was designed and manufactured, which is mainly composed of a three-axis computer numerical control (CNC) machine, a flexible supporting system, and a three-dimensional (3D) scanning feedback system. A series of forming experiments focusing on a gradual curvature shape were carried out using this prototype to investigate the feasibility and validity of this forming process.

Springback prediction of AL6061 pipe in free bending process based on finite element and analytic methods

2020 ◽  
Vol 109 (7-8) ◽  
pp. 1789-1799
Author(s):  
Yusen Li ◽  
Andi Li ◽  
Zhenming Yue ◽  
Liangyu Qiu ◽  
Houssem Badreddine ◽  
...  
Keyword(s):  
Finite Element ◽  
Analytic Methods ◽  
Bending Process ◽  
Springback Prediction ◽  
Free Bending

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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