Theoretical analysis on springback of L-section extrusion in rotary stretch bending process

2011 ◽  
Vol 21 (12) ◽  
pp. 2705-2710 ◽  
Author(s):  
Cheng-long YU ◽  
Xiao-qiang LI
Keyword(s):  
Theoretical Analysis ◽  
Stretch Bending ◽  
Bending Process

Research on springback characteristic in flexible multi-points 3D stretch-bending process

2021 ◽  
pp. 095440542110284
Author(s):  
Song Gao ◽  
Tonggui He ◽  
Qihan Li ◽  
Yingli Sun ◽  
Jicai Liang
Keyword(s):  
Simulation Model ◽  
High Efficiency ◽  
Vertical Direction ◽  
Factors Affecting ◽  
Stretch Bending ◽  
Element Simulation ◽  
Bending Process ◽  
Bending Radius ◽  
Aluminum Profiles ◽  
Bending Sequence

The problem of springback is one of the most significant factors affecting the forming accuracy for aluminum 3D stretch-bending parts. In order to achieve high-efficiency and high-quality forming of such kind of structural components, the springback behaviors of the AA6082 aluminum profiles are investigated based on the flexible multi-points 3D stretch-bending process (3D FSB). Firstly, a finite element simulation model for the 3D FSB process was developed to analyze the forming procedure and the springback procedure. The forming experiments were carried out for the rectangle-section profile to verify the effectiveness of the simulation model. Secondly, the influence of tension on springback was studied, which include the pre-stretching and the post-stretching. Furthermore, the influences of the bending radius and bending sequence are revealed. The results show that: (1) The numerical model can be used to evaluate the effects of bending radius and process parameters on springback in the 3D FSB process effectively. (2) The pre-stretching has little effect on the horizontal springback reduction, but it plays a prominent role in reducing the springback in the vertical direction. (3) The increase of bending deformation in any direction will lead to an increase of springback in its direction and reduce the springback in the other direction. Besides, it reduces the relative error in both directions simultaneously. This research established a foundation to achieve the precise forming of the 3D stretch-bending parts with closed symmetrical cross-section.

Forming Limits Under Stretch-Bending Through Distortionless and Distortional Anisotropic Hardening

2018 ◽  
Vol 140 (12) ◽  
Author(s):  
Ji He ◽  
Bin Gu ◽  
Yongfeng Li ◽  
Shuhui Li
Keyword(s):  
Detailed Comparison ◽  
Forming Limit ◽  
Anisotropic Hardening ◽  
Hardening Model ◽  
Stretch Bending ◽  
Bending Process ◽  
Hardening Models ◽  
Out Of Plane ◽  
Forming Limit Curves ◽  
Insight Into

The necking behavior of sheet metals under stretch-bending process is a challenge for the forming limit prediction. State-of-the-art forming limit curves (FLCs) allow the prediction under the in-plane stretching but fall short in the case under out-of-plane loading condition. To account for the bending and straightening deformation when sheet metal enters a die cavity or slide along a radius, anisotropic hardening model is essential to reflect the nonproportional loading effect on stress evolution. This paper aims to revisit the M-K analysis under the stretch-bending condition and extend it to accommodate both distortionless and distortional anisotropic hardening behavior. Furthermore, hardening models are calibrated based on the same material response. Then the detailed comparison is proposed for providing better insight into the numerical prediction and necking behavior. Finally, the evolution of the yield surface and stress transition states is examined. It is found that the forming limit prediction under stretch-bending condition through the M-K analysis strongly depends on the employed anisotropic hardening model.

scholarly journals Springback Study on Profile Flexible 3D Stretch-Bending Process Using the Neural Network

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Yi Li ◽  
Ce Liang ◽  
Xiangfeng Lin ◽  
Jicai Liang ◽  
Zhongyi Cai ◽  
...  
Keyword(s):  
Neural Network ◽  
Bp Neural Network ◽  
Material Properties ◽  
Simulation Analysis ◽  
Orthogonal Experiment ◽  
Range Analysis ◽  
Finite Element Software ◽  
Stretch Bending ◽  
Aluminum Profile ◽  
Bending Process

The springback is one of the main defects in the flexible 3D stretch-bending process. In this paper, according to the orthogonal design of experiments, the numerical simulation analysis of the springback for the 3D stretch-bending aluminum profile is carried out by the ABAQUS finite element software. And to investigate the effect of material properties on the springback, the range analysis of the orthogonal experiment is performed. The results show that these material properties of the aluminum profile (elastic modulus E, yield strength σy, and tangent modulus E1) might have the biggest influence on the springback of the aluminum profile, and the optimized forming parameters are founded as follows: the horizontal bending degree is 14°, the vertical bending degree is 14°, the number of multipoint stretch-bending dies is 10, the friction coefficient is 0.15, and aluminum alloy grade is 6063. Moreover, the model of the BP neural network for the prediction of the springback is established and trained based on the orthogonal experiment, and the results with the BP neural network model are in good agreement with experimental results. So it is obvious that the BP neural network could predict effectively the springback of 3D multipoint stretch-bending parts.

A Semi-Analytic Model to Predict and Compensate Springback in the 3D Stretch Bending Process

2013 ◽  
Vol 85 (4) ◽  
pp. 697-709 ◽  
Author(s):  
Juan Liao ◽  
Xin Xue ◽  
Chi Zhou ◽  
Frederic Barlat ◽  
Jose Gracio
Keyword(s):  
Analytic Model ◽  
Stretch Bending ◽  
Bending Process

Innovative Machine Concepts for 3D Bending of Tubes and Profiles

2011 ◽  
Vol 473 ◽  
pp. 37-42 ◽  
Author(s):  
Matthias Hermes ◽  
Daniel Staupendahl ◽  
Christoph Becker ◽  
A. Erman Tekkaya
Keyword(s):  
Cross Sections ◽  
Cost Efficiency ◽  
Three Dimensional ◽  
Free Form ◽  
Tube Bending ◽  
Stretch Bending ◽  
Bending Process ◽  
New Process ◽  
Spinning Process ◽  
Springback Reduction

The paper deals with two new processes and developed special machines for profile and tube bending. The first process is a new roll-based machine for three-dimensional bending of profiles with symmetrical and asymmetrical cross-sections that has been developed. Compared to conventional processes like stretch bending, the advantage of Torque Superposed Spatial (TSS) Bending is the kinematic adjustment of the bending contour, leading to higher flexibility and cost efficiency especially in small batch production. The second process is the new process of Incremental Tube Forming (ITF). This process is based on a combination of a spinning process and kinematic free form bending of tubular semi-finished products. It is suitable for bending tubes two- and three-dimensionally to arbitrary contours and for manufacturing tailored tubes. The combined spinning and bending process leads to low bending forces with the possibility of a significant springback reduction.

FEM-Based Simulation and Gripper Jaw Trajectory Fitting of Stretch-Bending Process for a Bending Beam of Railway Vehicles

2013 ◽  
Vol 372 ◽  
pp. 661-665
Author(s):  
Sheng Man Wang ◽  
Xin Hua Yang ◽  
Xing Lu
Keyword(s):  
Control Method ◽  
Die Design ◽  
Railway Vehicle ◽  
Fe Model ◽  
The Finite Element Method ◽  
Forming Process ◽  
Stretch Bending ◽  
Bending Process ◽  
Design Requirements ◽  
Displacement Control Method

The bending beam of railway vehicle is made of thin stainless steel, with large sizes and unsymmetrical section, and prone to defects during stretch-bending forming process, such as wrinkling, cross-section distortion and so on. A reasonable trajectory of gripper jaws could make for mitigating the mentioned defects. The Finite Element Method was employed to fit the trajectory as well as simulate the forming process. The FE model was built by using the commercial FE software Hypermesh and ABAQUS/CAE. The analysis was carried out based on dynamic explicit and displacement control method. On this basis, the actual stretch bending process was developed according to the fitted trajectory and simulated process. The actual production process indicates that the formed beam can meet the design requirements, and the method is feasible and economical, as well as can contribute to a better understanding of stretch bending process and die design.

Numerical Simulation of Stretch Bending Process and Springback for T Section Aluminum Extrusions

2006 ◽  
Vol 315-316 ◽  
pp. 416-420
Author(s):  
Ming He Chen ◽  
Lin Gao ◽  
H.H. Mao ◽  
Dun Wen Zuo ◽  
Min Wang
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Element Model ◽  
Major Effect ◽  
Experimental Results ◽  
Spring Back ◽  
Stretch Bending ◽  
Aluminum Extrusions ◽  
Bending Process ◽  
Forming Precision

In order to improve the forming precision of the stretch bending process for T section aluminum extrusions and meet the fine forming requirement of the aerostat blank parts, the elongation controlled stretch bending process finite element model is proposed, which is based on the basic principle of the stretch bending forming with respect to A-7B CNC Section Stretch Wrap Forming Machine by analyzing various factors that influence the qualities of stretch bending parts, and the numerical simulation of the stretch bending process and spring back for T section aluminum extrusions is carried out. The results of simulation show that the pre-stretching elongation has a major effect on stretch bending parts and finite post-stretching elongation helps to improve the forming qualities of the parts. Comparing with the experimental results, the spring back of the finite element simulation shows good agreement with that of the experimental results.

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