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.

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.

Comparison between an Advanced Numerical Simulation of Sheet Incremental Forming Using Adaptive Remeshing and Experimental Results

2013 ◽  
Vol 554-557 ◽  
pp. 1375-1381 ◽  
Author(s):  
Laurence Giraud-Moreau ◽  
Abel Cherouat ◽  
Jie Zhang ◽  
Houman Borouchaki
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Sheet Metal ◽  
Metal Forming ◽  
Tool Path ◽  
Incremental Forming ◽  
Computation Time ◽  
Experimental Results ◽  
Forming Process ◽  
Adaptive Remeshing

Recently, new sheet metal forming technique, incremental forming has been introduced. It is based on using a single spherical tool, which is moved along CNC controlled tool path. During the incremental forming process, the sheet blank is fixed in sheet holder. The tool follows a certain tool path and progressively deforms the sheet. Nowadays, numerical simulations of metal forming are widely used by industry to predict the geometry of the part, stresses and strain during the forming process. Because incremental forming is a dieless process, it is perfectly suited for prototyping and small volume production [1, 2]. On the other hand, this process is very slow and therefore it can only be used when a slow series production is required. As the sheet incremental forming process is an emerging process which has a high industrial interest, scientific efforts are required in order to optimize the process and to increase the knowledge of this process through experimental studies and the development of accurate simulation models. In this paper, a comparison between numerical simulation and experimental results is realized in order to assess the suitability of the numerical model. The experimental investigation is realized using a three-axis CNC milling machine. The forming tool consists in a cylindrical rotating punch with a hemispherical head. A subroutine has been developed to describe the tool path from CAM procedure. A numerical model has been developed to simulate the sheet incremental forming process. The finite element code Abaqus explicit has been used. The simulation of the incremental forming process stays a complex task and the computation time is often prohibitive for many reasons. During this simulation, the blank is deformed by a sequence of small increments that requires many numerical increments to be performed. Moreover, the size of the tool diameter is generally very small compared to the size of the metal sheet and thus the contact zone between the tool and the sheet is limited. As the tool deforms almost every part of the sheet, small elements are required everywhere in the sheet resulting in a very high computation time. In this paper, an adaptive remeshing method has been used to simulate the incremental forming process. This strategy, based on adaptive refinement and coarsening procedures avoids having an initially fine mesh, resulting in an enormous computing time. Experiments have been carried out using aluminum alloy sheets. The final geometrical shape and the thickness profile have been measured and compared with the numerical results. These measurements have allowed validating the proposed numerical model. References [1] M. Yamashita, M. Grotoh, S.-Y. Atsumi, Numerical simulation of incremental forming of sheet metal, J. Processing Technology, No. 199 (2008), p. 163 172. [2] C. Henrard, A.M. Hbraken, A. Szekeres, J.R. Duflou, S. He, P. Van Houtte, Comparison of FEM Simulations for the Incremental Forming Process, Advanced Materials Research, 6-8 (2005), p. 533-542.

Stress Analysis of Sheet Metal Vibration Incremental Forming

2010 ◽  
Vol 154-155 ◽  
pp. 166-170
Author(s):  
Gai Pin Cai ◽  
Ning Yuan Zhu ◽  
Na Wen
Keyword(s):  
Sheet Metal ◽  
Incremental Forming ◽  
Low Frequency ◽  
Forming Process ◽  
Technical Parameters ◽  
Vibration Technique ◽  
Low Frequency Vibration ◽  
Metal Deformation ◽  
Angle Effect ◽  
Forming Angle

As a non-homogenous force stresses during incremental forming, sheet metal easily tended to instability, and some defects, such as deposition, wrinkle and fracture, would appear. If the vibration technique was combined the incremental forming process, its deformation mechanism would be different from that of the old process, and sheet metal deformation quality was also risen. Then some mechanical equations were built by force analyzed on element in local contact zone of die head forcing down. According to reasonable hypothesis and simplified, the equations were solved. Some stress-time curves of the element were obtained by given process parameters, vibrational parameters and time parameters. It is shown from analysis that stress variety of the element is closely related to amplitude, frequency and forming angle, effect of sheet metal vibration incremental forming with high frequency vibration is more superior than that of with low frequency vibration; only when vibrational parameters are reasonably matching technical parameters, the effective vibration incremental forming can be obtained.

Effects of Tool Deflection in Accumulated Double-Sided Incremental Forming Regarding Part Geometry

2016 ◽  
Author(s):  
Huaqing Ren ◽  
Newell Moser ◽  
Zixuan Zhang ◽  
Kornel F. Ehmann ◽  
Jian Cao
Keyword(s):  
Sheet Metal ◽  
Relative Position ◽  
Capital Investment ◽  
Incremental Forming ◽  
Position Angle ◽  
Tool Deflection ◽  
Geometric Accuracy ◽  
Localized Deformation ◽  
Forming Process ◽  
Part Geometry

Incremental forming is a flexible dieless forming process. In incremental forming, the metal sheet is clamped around its periphery. One or multiple generic stylus-type tools move along a predefined toolpath, incrementally deforming the sheet metal into a final, freeform shape. Compared with the traditional sheet metal forming process, the incremental forming process is more flexible, energy efficient and cost effective due to lower capital investment related to tooling. However, maintaining tight geometric tolerances in incremental formed parts can be a challenge. Specifically, undesired global bending is usually induced near the region between the tools and fixture resulting in a compromise in geometric accuracy. To address this issue, Accumulated Double-Sided Incremental Forming (ADSIF) is proposed, which utilizes two tools on both sides of the metal to better achieve localized deformation while simultaneously constraining global bending outside the forming area. Moreover, in ADSIF, the two tools are moving from inward to outward, and thus the tools are always forming virgin material and so as to limit forces on the already-formed part. Thus, ADSIF has a higher potential to achieve the desired geometry. Nevertheless, tool deflection due to machine compliance is still an issue that can have a considerable effect on geometric accuracy. In this work, the effect of tool deflection related to part geometry is studied for the ADSIF process. The nature of using two tools, rather than one, in ADSIF inherently implies that relative tool position is a critical process parameter. It is the region near these two tools where local squeezing and bending of the sheet occurs, the primary modes of deformation found in ADSIF. The change of relative tool positions (i.e., tool gap and relative position angle) are studied in detail by first developing an analytical model. It is concluded that the tool gap will be enlarged under the influence of tool compliance while the relative position angle is less affected. Additionally, a finite element simulation capable of modeling tool deflection is established. The comparison between the simulation results using rigid tools and deformable ones clearly demonstrated the significant influence of tool compliance on part geometry. Lastly, an axisymmetric part with varying wall angles was formed, and it was confirmed that ADSIF demonstrates improved geometry accuracy compared with conventional Double-Sided Incremental Forming.

Finite Element Analysis of Incremental Sheet Forming for Metal Sheet

2018 ◽  
Vol 783 ◽  
pp. 148-153
Author(s):  
Muhammad Sajjad ◽  
Jithin Ambarayil Joy ◽  
Dong Won Jung
Keyword(s):  
Mechanical Properties ◽  
Sheet Metal ◽  
Tool Path ◽  
Incremental Forming ◽  
Single Point ◽  
Machining Process ◽  
Machining Parameters ◽  
Forming Process ◽  
Element Analysis ◽  
Tool Diameter

Incremental sheet metal forming, is a non-conventional machining process which offers higher formability, flexibility and low cost of production than the traditional conventional forming process. Punch or tool used in this forming process consecutively forces the sheet to deform locally and ultimately gives the target profile. Various machining parameters, such as type of tool, tool path, tool size, feed rate and mechanical properties of sheet metal, like strength co-efficient, strain hardening index and ultimate tensile strength, effects the forming process and the formability of final product. In this research paper, Single Point Incremental Forming was simulated using Dassault system’s Abaqus 6.12-1 and results are obtained. Results of sheet profile and there change in thickness is investigated. For this paper, we simulated the process in abaqus. The tool diameter and rotational speed is find out for the production of parts through incremental forming. The simulation is done for two type of material with different mechanical properties. Various research papers were used to understand the process of incremental forming and its simulation.

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.

scholarly journals Common defects of parts manufactured through single point incremental forming

2021 ◽  
Vol 343 ◽  
pp. 04007
Author(s):  
Mihai Popp ◽  
Gabriela Rusu ◽  
Sever-Gabriel Racz ◽  
Valentin Oleksik
Keyword(s):  
Sheet Metal ◽  
Metal Forming ◽  
Incremental Forming ◽  
Single Point ◽  
Single Point Incremental Forming ◽  
Forming Process ◽  
Metal Forming Process ◽  
Serial Robot ◽  
The Many ◽  
Cold Metal

Single point incremental forming is one of the most intensely researched die-less manufacturing process. This process implies the usage of a CNC equipment or a serial robot which deforms a sheet metal with the help of a relatively simple tool that follows an imposed toolpath. As every cold metal forming process, besides the many given advantages it has also some drawbacks. One big drawback in comparison with other cold metal forming processes is the low accuracy of the deformed parts. The aim of this research is to investigate the sheet metal bending mechanism through finite element method analysis. The results shows that the shape of the retaining rings has a big influence over the final geometrical accuracy of the parts manufactured through single point incremental forming.

3D Loading Path-Generating Method for FEM Simulation of Incremental Sheet Metal Forming Process

2010 ◽  
Vol 97-101 ◽  
pp. 2810-2815 ◽  
Author(s):  
Yan Xu ◽  
Shuang Gao Li ◽  
Lin Gao
Keyword(s):  
Sheet Metal ◽  
Incremental Forming ◽  
Thickness Distribution ◽  
Fem Simulation ◽  
Loading Path ◽  
Forming Process ◽  
Forming Simulation ◽  
Generating Method ◽  
Incremental Sheet Metal Forming ◽  
3D Loading

Incremental forming of sheet metal is difficult to be simulated for its complicated 3D loading path. In this work, an acceptable approach to generate 3D loading path, called “virtual guiding model method” is accomplished. The method, which has the similar idea with the conventional copy mill, is based on FEM and the basic principle of kinematics. With the help of the method, multi-stage incremental forming of a drawing typed square cup was simulated in the FEM software-PAMSTAMP and experimented. Through measuring the thickness distribution the vertical edge of the cup, the most difference between them is less than 0.05mm, which is satisfied with engineering request, and the results shows that the 3D loading path generating method is one of the most effective way to realize the incremental forming simulation.

scholarly journals TENDENCIES IN FORMING SHEET METAL PARTS USING INCREMENTAL FORMING ADVANCED TECHNOLOGIES

2019 ◽  
Vol 25 (3) ◽  
Author(s):  
CATALINA CIOFU ◽  
BOGDAN CHIRITA ◽  
ROXANA LUPU ◽  
COSMIN GRIGORAS ◽  
CRINA RADU ◽  
...  
Keyword(s):  
Sheet Metal ◽  
Incremental Forming ◽  
Stretch Forming ◽  
Micro Forming ◽  
Forming Process ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
Advanced Technologies ◽  
Metal Materials ◽  
Forming Methods

Stretch forming of sheet metal materials is a highly required process in aerospace industry for manufacturing skin parts. Automation of some processes such as cutting, punching, forming, shearing and nesting in conventional manufacturing tends to combine these forming methods. Some researches are made on the formability of sheet metal materials obtained in incremental forming process with stretch forming and water jet incremental micro-forming with supporting dies. This paper is an attempt to review the newly researches made on optimization of manufacturing metal skin parts to achieve geometrical accuracy.

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