A Novel Incremental Bending Process of Complex Curved Sheet Metal

2016 ◽  
Author(s):  
Qiyang Zuo ◽  
Kai He ◽  
Zhigang Sun ◽  
Hui Xu ◽  
Wei Li ◽  
...  
Keyword(s):  
Steel Plate ◽  
Feedback System ◽  
3D Scanning ◽  
Ship Hull ◽  
Work Piece ◽  
Forming Process ◽  
Supporting System ◽  
Bending Process ◽  
Incremental Punching ◽  
Curved Steel

The bending of complex curved sheet metals of ship hull has long been a challenge in shipbuilding yard on account of some inherent defects of the traditional forming processes such as the line heating. This paper presents a novel incremental bending process based on punching to obtain complex curved steel plates in order to take the place of those inefficient traditional forming processes of ship hull. The presented incremental bending process is carried out by a series of stepping punches, so it is also defined as incremental punching in this work. By means of this process, the blank plate that is fixed and held by a flexible supporting system can incrementally be bent to the target shape by a press tool with a planned tool trajectory one step after another. Meanwhile, in order to improve geometric accuracy of the formed work-piece, a 3D scanning feedback system is applied to measure the deformation of the work-piece during the forming process. Three dimensional shape of the formed work-piece can be imaged and rebuilt with a large amount of point cloud data by the 3D scanning feedback system. Then the difference between the rebuilt model of the formed work-piece and the target CAD-model can be acquired, which can be used for feedback control of the forming accuracy if necessary. To validate the presented forming process, an original incremental punching prototype was designed and manufactured, which is mainly composed of a 3-axis CNC machine, a flexible supporting system and a 3D scanning feedback system. A forming experiment of a gradual curvature steel plate was carried out using this prototype and is discussed in detail in this paper in order to demonstrate the feasibility of the proposed incremental bending process of complex curved steel plate.

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.

A NEW TYPE OF INCREMENTAL BENDING METHOD FOR COMPLICATED CURVED SHEET METAL

2016 ◽  
Vol 40 (4) ◽  
pp. 433-443 ◽  
Author(s):  
Jiuhua Li ◽  
Xiaobing Dang ◽  
Kai He ◽  
Qiyang Zuo ◽  
Ruxu Du
Keyword(s):  
Sheet Metal ◽  
Incremental Forming ◽  
Minimum Energy ◽  
3D Scanning ◽  
Scanning System ◽  
Forming Process ◽  
Supporting System ◽  
Blank Sheet ◽  
Bending Process ◽  
New Type

A new type of incremental bending process for complicated curved sheet metal is proposed in the paper. The blank sheet is bended incrementally step by step. To validate the forming process, an incremental bending prototype is designed and manufactured, which was composed of a 3-DOF working table, a flexible supporting system and a 3D scanning system. The forming trajectory based on the theory of the minimum energy is planned according to the designed model of the sheet metal. Several experiments are carried out and the designed part is manufactured, which validated the proposed incremental forming method was successful.

scholarly journals Effect of Spring Back on Formation Process of Sheet Metal Bending Plates

Teknomekanik ◽  
2020 ◽  
Vol 3 (1) ◽  
pp. 28-35
Author(s):  
Purwantono Purwantono ◽  
Nelvi Erizon ◽  
Nofri Helmi ◽  
Muhammad Akhbar ◽  
Muhibuddin Muhibuddin
Keyword(s):  
Sheet Metal ◽  
Room Temperature ◽  
Steel Plate ◽  
Metal Plate ◽  
Spring Back ◽  
Forming Process ◽  
Bending Angle ◽  
Small Deviations ◽  
Bending Process ◽  
Bending Plates

This study aims to observe the amount of deviation that occurs due to the influence of spring back on the forming process. spring back in question is the back force when the plate undergoes a forming process, but when the load is released, the plate condition will reverse or return to its initial condition. This reversal is due to the factor of the elasticity of the material that is owned. Other factors that influence the bending process include thickness, width, angle of bending and others. object of this research is a sheet metal plate with a thickness of 1 mm - 4 mm. Forming process is done by bending process. This bending process is widely used in the plate forming process, namely to bend the sides of the plate to make it stiffer. This bending process is carried out in cold conditions where the process is carried out at room temperature. This research was conducted by preparing slices of the same width and length and then the process of bending them to form an angle of 20 ° to 120 °. results of this test indicate that the thicker the bent material has the tendency to produce small deviations. This means that the value of the spring back ratio also decreases. The value of the spring back ratio in this study ranges from 1% to 9%. This means that if the bending process is carried out on a steel plate with the resulting bending angle of 90 °, the bending angle of the shoe must be more than 90 °, the excess is 1 ° - 9 °. So that when the load is released, the position of the susdut bends closer to 90 °.

Effects of Part Geometry on Spring-Back/Spring-Go Feature in U-Bending Process

2013 ◽  
Vol 549 ◽  
pp. 100-107 ◽  
Author(s):  
Wiriyakorn Phanitwong ◽  
Arkarapon Sontamino ◽  
Sutasn Thipprakmas
Keyword(s):  
Laboratory Experiments ◽  
Fem Simulation ◽  
Work Piece ◽  
Spring Back ◽  
Forming Process ◽  
Bending Angle ◽  
Part Geometry ◽  
Bending Process ◽  
Metal Forming Process ◽  
Simulation Results

The U-bending process is a common sheet-metal forming process widely employed to fabricate sheet parts like channels, beams, and frames of various sizes applied in almost all industrial fields. In recent years, the precision requirements are increased on the U-bent parts. To achieve these requirements, in this study, the effects of part geometry on the spring-back/spring-go feature including work piece length, U-channel width, punch and die radii, and work piece thickness, were investigated by using the finite element method (FEM) and laboratory experiments. The FEM simulation results clearly revealed the influence of part geometry on spring-back/spring-go feature via the changes of stress distribution analyses on the bending allowance zone, the bottom of bent part, and the U-leg of bent part. Specifically, the part geometry affected on the bending characteristic on the bending allowance zone, as well as it affected on the spring-back feature. In addition, the part geometry also affected on the formation of reversed bending characteristic on the bottom and U-leg of bent parts, as well as it affected on the spring-go feature. The bending angle could be achieved by compensating these bending and reversed bending characteristics. Therefore, to meet the required bending angle, the suitable design of part geometry was strongly considered to maintain the balancing of the bending and reversed bending characteristics. The laboratory experiments were carried out to validate the accuracy of the FEM simulation results. The FEM simulation results showed good agreement with the experimental results with reference to the bending angle and bending force.

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.

Prediction of Deformations of Steel Plate by GEP in Forming Process

2012 ◽  
Vol 544 ◽  
pp. 268-273
Author(s):  
Lei Yang ◽  
Liang Gao
Keyword(s):  
Mathematical Model ◽  
Influencing Factors ◽  
Steel Plate ◽  
Heating Process ◽  
Forming Process ◽  
Line Heating ◽  
Main Method ◽  
Plate Deformation ◽  
Final Deformation

Line heating is the main method for forming compound curved shells of hull. The accuracy of final deformation and the productivity depend on the experience of the workers. To predict the plate deformation, the explicit mathematical model for deformation and the main influencing factors by FEA and GEP is established in this paper. The main influencing factors in line heating process were analyzed firstly. Then, 16 group deformation results of steel plate under the five main influencing factors were obtained by FEA. At last, the explicit mathematical model for deformation and the main influencing factors was established.

Principle and Simulation Study on Multi Point-Single Point Incremental Combined Forming for Sheet Metal

2009 ◽  
Vol 626-627 ◽  
pp. 273-278 ◽  
Author(s):  
X.J. Li ◽  
Ming Zhe Li ◽  
C.G. Liu ◽  
Zhong Yr Cai
Keyword(s):  
Sheet Metal ◽  
Single Point ◽  
Experimental Result ◽  
Work Piece ◽  
The Novel ◽  
Forming Process ◽  
Explicit Finite Element ◽  
Forming Defect ◽  
Forming Technology ◽  
Elastic Cushion

Based on Multi-Point (MP) forming technology and Single-Point Incremental (SPI) forming technology, MP-SPI combined forming method for sheet metal is proposed, the principle and two different forming techniques are illustrated firstly. Then the paper is focused on numerical analysis for the novel forming technique with explicit Finite Element (FE) algorithm. During simulation of spherical work-piece, dimpling occurs as a main forming defect in MP-SPI combined forming process. Simulation results show that the dimpling defect can be suppressed effectively by using elastic cushion. An appropriate thickness of elastic cushion is necessary to prevent dimpling. And also the deformation of the work-piece is sensitive to the shape of elastic cushion. The combined forming test shows that the numerical simulation result is closed to the experimental result.

CHARACTERIZATION AND ANALYSES ON RESIDUAL STRESS AND DEFORMATION DISTRIBUTION IN LINE HEAT PROCESS

2021 ◽  
Vol 158 (A4) ◽  
Author(s):  
B Zhou ◽  
X Han ◽  
W Guo ◽  
Z Liu ◽  
S-K Tan
Keyword(s):  
Residual Deformation ◽  
Element Model ◽  
Heating Process ◽  
Stress Distributions ◽  
Forming Process ◽  
Line Heating ◽  
Bending Process ◽  
Stress And Deformation ◽  
The Impact ◽  
Residual Stress And Deformation

Line heating is an important plate bending process that has been adopted in shipyards for more than 60 years. This paper presents the results of a numerical and experimental study on the residual deformation and stress distribution in the plate forming process using the line heating method. In this paper, a finite element model was used to simulate the heating process, and the model was validated using experimental results. The model was then used to analyze the deformation and stress distributions in the heating and non-heating region. The impact of line heating and sequence of heating on both sides of a steel plate was discussed. The findings of the study show that the compression stress generated help to increase the shrinkage of line heating process. This study presents a valuable reference for similar thermal process.

Theoretical Investigation of the Bending Process of the Pre-Strained Metal Sheet

2020 ◽  
Vol 299 ◽  
pp. 351-357
Author(s):  
Sergey A. Tipalin ◽  
Michael A. Petrov ◽  
Yuriy A. Morgunov
Keyword(s):  
Thin Sheet ◽  
Bending Moment ◽  
Metal Sheet ◽  
Roll Forming ◽  
Forming Process ◽  
Bending Process ◽  
Punch Radius ◽  
Zero Radius ◽  
Strain Stress ◽  
Roll Forming Process

During the bending operation of the thin sheet materials by the punch with the near-to-zero radius the special technological operation should be carried out. It means that the metal sheet obtained a certain thinning value, which is usually done in the form of the channel-concentrator or groove by pre-drawing operation in a cold state. It follows to the pre-straining and strengthening of the material. The authors investigated the strain hardened sheet's area after roll forming process theoretically, and obtained the strain-stress distribution inside the sheet during the bending operation. It was found out that the increase of the prior deformation during pre-straining in the bend layer follows to the increase of the radial and tangential stresses and displacement of the neutral axis inside the blank during bending operation. As a result, the bending moment changes its values depends on the punch radius and strain hardening.

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