Effect of Toolpath on the Springback of 2024-T3 Aluminum During Single Point Incremental Forming

2015 ◽  
Author(s):  
Zachary C. Reese ◽  
Brandt J. Ruszkiewicz ◽  
Chetan P. Nikhare ◽  
John T. Roth
Keyword(s):  
Residual Stresses ◽  
Sheet Metal ◽  
Tool Path ◽  
Incremental Forming ◽  
Single Point ◽  
Final Part ◽  
Cnc Milling ◽  
Forming Process ◽  
Step Size ◽  
Part Geometry

Incremental forming is a nontraditional forming method in which a spherical tool is used to asymmetrically deform sheet metal without the need for expensive allocated dies. Incremental forming employs a tool path similar to that used when CNC milling. Hence, when forming a part, the forming tool makes a series of passes circumferentially around the workpiece, gradually spirally stepping down in the z-axis on each sequential pass. This tool path deforms the sheet metal stock into the final, desired shape. These passes can start from the outer radius of the part and work in (Out to In, OI forming) or they can start from the center of the shape and work outward (In to Out, IO forming). As with many sheet metal operations, springback is a big concern during the incremental forming process. During the deformation process, residual stresses are created within the workpiece causing the final formed shape to springback when it is unclamped, sometimes very significantly. The more complex the geometry of the final part and the more total deformation that occurs when forming the geometry, the greater the residual stresses that are generated within the part. The residual stresses that have built up in the piece cause more significant distortion to the part when it is released from the retaining fixturing. This paper examines how the step size (in the z direction), OI vs. IO forming, and final part geometry affect the total springback in a finished piece. For all of these tests 0.5 mm thick sheets of 2024-T3 aluminum were used to form both the truncated pyramid and truncated cone shape. From this investigation it was found that smaller step sizes result in greater springback, IO is significantly less effective in forming the part (due to workpiece tearing), and final part geometry plays an important role due to the creation of residual stresses that exist in corners.

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.

Investigations about the Single Point Incremental Forming of Anisotropic Titanium Alloy Sheets

2011 ◽  
Vol 264-265 ◽  
pp. 188-193 ◽  
Author(s):  
G. Palumbo ◽  
Marco Brandizzi ◽  
G. Cervelli ◽  
M. Fracchiolla
Keyword(s):  
Tool Path ◽  
Incremental Forming ◽  
Single Point ◽  
Tensile Tests ◽  
Single Point Incremental Forming ◽  
Cnc Milling ◽  
Forming Process ◽  
Fe Simulations ◽  
Shape Errors ◽  
Optical Strain

The present work focuses the attention on the Single Point Incremental Forming (SPIF) of the Titanium (Ti) alloy Ti-6Al-4V. Tensile tests were carried out using the optical strain measurement system Aramis3D, in order to determine the mechanical behaviour of the alloy and to investigate the anisotropy of such alloy. Finite Element (FE) simulations of the SPIF process (using ABAQUS/explicit) were performed using a simple but non-axialsymmetric shape (truncated pyramid) with the aim of investigating the effect of both the tool/pitch ratio (D/p) and the draw angle (α), taking into account the anisotropic behaviour. The analysis of plastic strains and thinning maps, together with the evaluation of shape errors originated by the forming process, highlighted that the parameter D/p plays a key role in the SPIF. Results from the preliminary FE analysis were used for investigating the production by SPIF of an automotive component (car door shell). A specific subroutine was created by the authors for automatically generating the tool path to be used in both the FE simulations and the manufacturing of parts by SPIF on a CNC milling machine.

scholarly journals Tool Path Design of the Counter Single Point Incremental Forming Process to Decrease Shape Error

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4719
Author(s):  
Kyu-Seok Jung ◽  
Jae-Hyeong Yu ◽  
Wan-Jin Chung ◽  
Chang-Whan Lee
Keyword(s):  
Sheet Metal ◽  
Tool Path ◽  
Incremental Forming ◽  
Single Point ◽  
Optimization Method ◽  
Single Point Incremental Forming ◽  
Shape Error ◽  
Forming Process ◽  
Two Stage ◽  
Shape Errors

Incremental sheet metal forming can manufacture various sheet metal products without a dedicated punch and die set. In this study, we developed a two-stage incremental forming process to decrease shape errors in the conventional incremental forming process. The forming process was classified into the first single point incremental forming (1st SPIF) process for forming a product and the counter single point incremental forming (counter SPIF) process to decrease shape error. The counter SPIF gives bending deformation in the opposite direction. Furthermore, the counter SPIF compensates for shape errors, such as section deflection, skirt spring-back, final forming height, and round. The tool path of the counter SPIF has been optimized through a relatively simple optimization method by modifying the tool path of the previous step. The tool path of the 1st SPIF depends on the geometry of the product. An experiment was performed to form a circular cup shape to verify the proposed tool path of the 1st and counter SPIF. The result confirmed that the shape error decreased when compared to the conventional SPIF. For the application, the ship-hull geometry was adopted. Experimental results demonstrated the feasibility of the two-stage incremental forming process.

Experimental Tests to Study Feasibility and Formability in Incremental Forming Process

2009 ◽  
Vol 410-411 ◽  
pp. 391-400 ◽  
Author(s):  
Aldo Attanasio ◽  
Elisabetta Ceretti ◽  
Antonio Fiorentino ◽  
Luca Mazzoni ◽  
Claudio Giardini
Keyword(s):  
Tool Path ◽  
Incremental Forming ◽  
Single Point ◽  
Sheet Thickness ◽  
Experimental Tests ◽  
Final Part ◽  
Cnc Machine ◽  
Forming Process ◽  
Metal Forming Process ◽  
Sheet Formability

This paper deals with Incremental Sheet Forming (ISF), a sheet metal forming process, that knew a wide development in the last years. It consists of a simple hemispherical tool that, moving along a defined path by means of either a CNC machine or a robot or a self designed device, locally deforms a metal sheet. A lot of experimental and simulative researches have been conducted in this field with different aims: to study the sheet formability and part feasibility as a function of the process parameters; to define models able to forecast the final sheet thickness as a function of the drawing angle and tool path strategy; to understand how the sheet deforms and how formability limits can be defined. Nowadays, a lot of these topics are still open. In this paper, the results obtained from an experimental campaign performed to study sheet formability and final part feasibility are reported. The ISF tests were conducted deforming FeP04 deep drawing steel sheet 0.8 mm thick and analyzing the influence of the tool path strategy and of the adopted ISF technique (Single Point Incremental Forming Vs. Two Points Incremental Forming). The part feasibility and formability were evaluated considering final sheet thickness, geometrical errors of the final part, maximum wall angle and depth at which the sheet breaks. Moreover, process forces measurements were carried out by means of a specific device developed by the Authors, allowing to obtain important information about the load acting on the deforming device and necessary for deforming sheet.

Compensations for Tool Path to Enhance Accuracy During Double Sided Incremental Forming

2015 ◽  
Author(s):  
Rakesh Lingam ◽  
Anirban Bhattacharya ◽  
Javed Asghar ◽  
N. Venkata Reddy
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Tool Path ◽  
Incremental Forming ◽  
Single Point ◽  
Three Dimensional ◽  
Geometric Accuracy ◽  
Forming Process ◽  
Incremental Sheet Metal Forming

Incremental Sheet Metal Forming (ISMF) is a flexible sheet metal forming process that enables forming of complex three dimensional components by successive local deformations without using component specific tooling. ISMF is also regarded as die-less manufacturing process and in the absence of part-specific dies, geometric accuracy of formed components is inferior to that of their conventional counterparts. In Single Point Incremental Forming (SPIF), the simplest variant of ISMF, bending near component opening region is unavoidable due to lack of support. The bending in the component opening region can be reduced to a larger extent by another variant of ISMF namely Double Sided Incremental Forming (DSIF) in which a moving tool is used to support the sheet locally at the deformation zone. However the overall geometry of formed components still has unacceptable deviation from the desired geometry. Experimental observation and literature indicates that the supporting tool loses contact with the sheet after forming certain depth. Present work demonstrates a methodology to enhance geometric accuracy of formed components by compensating for tool and sheet deflection due to forming forces. Forming forces necessary to predict compensations are obtained using force equilibrium method along with thickness calculation methodology developed using overlap that occurs during forming (instead of using sine law). Results indicate that there is significant improvement in accuracy of the components produced using compensated tool paths.

CAD/CAM Strategies for a Parallel Kinematics SPIF Machine

2013 ◽  
Vol 554-557 ◽  
pp. 2221-2229 ◽  
Author(s):  
João B.S. Farias ◽  
Miguel A.B.E. Martins ◽  
Daniel G. Afonso ◽  
Sonia R.H. Marabuto ◽  
Jorge A. Ferreira ◽  
...  
Keyword(s):  
Tool Path ◽  
Incremental Forming ◽  
Single Point ◽  
Single Point Incremental Forming ◽  
Cnc Milling ◽  
Parallel Kinematics ◽  
Forming Process ◽  
Advantages And Disadvantages ◽  
Cad Cam ◽  
Five Axis

Single point incremental forming has attracted the interest of researchers in the last decade for the production of prototypes and small batch production of sheet-based parts [1, 2]. This technique allows the manufacture of parts without using expensive die sets. The SPIF (Single point incremental forming) process can be performed on different equipments such as adapted CNC milling machines, serial robots and built proposed machines [3]. Every solution has advantages and disadvantages. This work presents the CAD/CAM strategies for a parallel kinematics SPIF machine, designed and built at the University of Aveiro [3]. This machine brings a new approach to the SPIF industry. The machinery used to perform SPIF operations has limitations in their work volume with limited movements and in the magnitude of applicable forces. With that in mind, this machine was projected to overcome that obstacle, and was provided with a system with 6 degrees of freedom, while maintaining the ability to apply high loads. The disadvantage is the increase in volume occupied by the kinematic system. The manufacture of new parts could be reached out with more flexibility on the chosen tool path. The first step is the product design in the commercial CAD system. Next step is generating the tool path of the forming tool. This step is very important to achieve the desired part shape. It is used a commercial CAM system (EdgeCAM 2012®), which has resources from three up to five axis strategies. The last step is to send the information to the machine’s control system, based on real-time software. This paper will describe each step with more details.

Creating Helical Tool Paths for Single Point Incremental Forming

2007 ◽  
Vol 344 ◽  
pp. 583-590 ◽  
Author(s):  
M. Skjoedt ◽  
M.H. Hancock ◽  
N. Bay
Keyword(s):  
Tool Path ◽  
Incremental Forming ◽  
Single Point ◽  
Angular Position ◽  
Work Piece ◽  
Single Point Incremental Forming ◽  
Cnc Milling ◽  
Forming Process ◽  
Major Disadvantage ◽  
Continuous Feed

Single point incremental forming (SPIF) is a relatively new sheet forming process. A sheet is clamped in a rig and formed incrementally using a rotating single point tool in the form of a rod with a spherical end. The process is often performed on a CNC milling machine and the tool movement is programed using CAM software intended for surface milling. Often the function called profile milling or contour milling is applied. Using this milling function the tool only has a continuous feed rate in two directions X and Y, which is the plane of the undeformed sheet. The feed in the vertical Z direction is done in the same angular position in the XY plane along a line down the side of the work piece. This causes a scarring of the side and also results in a peak in the axial force when the tool is moved down. The present paper offers a solution to this problem. A dedicated program uses the coordinates from the profile milling code and converts them into a helical tool path with continuous feed in all three directions. Using the helical tool path the scarring is removed, the part is otherwise unchanged and a major disadvantage of using milling software for SPIF is removed. The solution is demonstrated by SPIF of three different geometries: a pyramid, a cone and a complex part.

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.

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.

Determination of Technological Forces in the Incremental Forming Process

2013 ◽  
Vol 371 ◽  
pp. 133-137
Author(s):  
Radu Eugen Breaz ◽  
Melania Tera ◽  
Octavian Bologa ◽  
Sever Gabriel Racz
Keyword(s):  
Image Processing ◽  
Theoretical Model ◽  
Data Acquisition ◽  
Incremental Forming ◽  
Single Point ◽  
Cnc Milling ◽  
Forming Process ◽  
Feed Drive ◽  
Cnc Milling Machine

The paper presents a joint theoretical and experimental approach to determine the technological forces within the asymmetric single point incremental forming ASPIF process, based upon a theoretical model, image processing and data acquisition. The first step of this approach was to develop a theoretical model of the forces within the process, based upon the model of a mechanical feed drive of a CNC milling machine. By means of this model, relationships between the resistant torque at the motor spindle level and the technological force on the movement axis could be determined. Using an image processing method, which allowed the user to extract information within the machines operator panel and analytical relationships, the technological forces were determined. The results were compared with the measured values, obtained by means of a data acquisition system.

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