Electrically Assisted Global Springback Elimination After Single Point Incremental Forming

2016 ◽  
Author(s):  
Trey Neveux ◽  
Brandt J. Ruszkiewicz ◽  
Tyler Grimm ◽  
John T. Roth ◽  
Ihab Ragai
Keyword(s):  
Residual Stress ◽  
Electric Current ◽  
Tool Path ◽  
Incremental Forming ◽  
Single Point ◽  
Appreciable Effect ◽  
Forming Process ◽  
Milling Operations ◽  
Path Testing ◽  
Springback Reduction

There has been a push in the automotive and aerospace industries towards die-less forming processing that are able to reduce both part cost and part energy. Incremental forming is a die-less forming process that fabricates parts using hemispherical tools following a tool path (similar to that found with conventional milling operations), that slowly deforms the sheet metal into the final desired configuration. Global springback for incremental forming, as defined herein, occurs after the part is unclamped from the retaining fixture. This form of springback is currently a significant impediment to the process since, when the part is released, the residual stresses created during the forming process result in significant part distortion and thereby, undesirable part geometries. To reduce this issue, this paper examines the effect on direct electric current on residual stress and springback elimination when applied post forming, which previous work has shown the potential to reduce this issue. This work is an extension of previous work resented at MSEC 2015. The previous work examined applying electric current to areas of high residual stress through the material’s thickness. This work examines the effect of applying electric current along the length and width of a part (path testing). This work concludes that running multiple paths increases springback reduction and the order in which the path testing is conducted has very little appreciable effect on the springback reduction during path testing.

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 Study on Using Cover Blank in Single Point Incremental Forming Process by Finite Element Analysis

2015 ◽  
Vol 809-810 ◽  
pp. 277-282
Author(s):  
Khalil Ibrahim Abass
Keyword(s):  
Tool Path ◽  
Incremental Forming ◽  
Sheet Material ◽  
Single Point ◽  
Complex Nature ◽  
Work Piece ◽  
Process Conditions ◽  
Single Point Incremental Forming ◽  
Forming Process ◽  
Highly Nonlinear

The Single Point Incremental Forming Process (SPIF) is a forming technique of sheet material based on layered manufacturing principles. The forming tool is moved along the tool path while the edges of sheet material are clamped. The finished part is manufactured by the CNC machine. SPIF involves extensive plastic deformation and the description of the process is more complicated by highly nonlinear boundary conditions, namely contact and frictional effects have been accomplished. However, due to the complex nature of these models, numerical approaches dominated by the FEA are now in widespread use. The paper presents the data and main results of a study on effect of using cover blank in SPIF through FEA. The considered SPIF has been studied under certain process conditions referring to the test work piece, tool, etc., applying ANSYS 11.0. The results show that the simulation model can predict an ideal profile of processing track, spring back error of SPIF, the behavior of contact tool-work piece, the product accuracy by evaluation its thickness and strain distributions, the contact status and chattering among surface interface tool-work piece.

Integrated Process Design for Two Robots Based Incremental Sheet Metal Forming

2012 ◽  
Vol 504-506 ◽  
pp. 877-882
Author(s):  
Dieter Kreimeier ◽  
Jun Hong Zhu ◽  
R. Laurischkat
Keyword(s):  
Process Design ◽  
Tool Path ◽  
Production Systems ◽  
Incremental Forming ◽  
Single Point ◽  
Industrial Robots ◽  
Integrated Process ◽  
Forming Process ◽  
Incremental Sheet Metal Forming ◽  
Supporting Tool

With the use of two industrial robots, Roboforming is a dieless incremental forming process, which is developed by the Chair of Production Systems at the Ruhr-University of Bochum. Connected to a cooperating robot system, these two robots hold respectively a forming and a supporting tool. Suitable for rapid prototyping and manufacture of small batch sizes with low costs, this forming process is based on flexible shaping through the synchronous movement of two industrial robots. Different from other single point incremental forming (SPIF) methods, the supporting tool used here greatly increases the geometric accuracy and the limited draw angle. A new processing technology always needs the computer-aided planning and simulation, which could accelerate the whole process and also give users the possibility to analyse and improve the process. In this paper, the whole integrated process design is introduced. After the modelling of the target CAD geometry, a self-developed CAM solution is used to get both tools’ positions and orientations according to the points on the geometrical surface. Based on the different forming strategies used, the supporting tool can even be synchronously placed at different positions on the sheet backside. After the tool path planning, the paths are first inputted into a simulation environment, which is consistent with the settings in the pilot plant. The tool positions and each robot’s postures can be seen and validated during the simulation. Before the final forming experiment, the tool paths are also sent into another simulation model for the forming analysis with the use of FEM technology. With consideration of many real material properties like springback and the subsequent deformation, the formed CAD geometry from the simulation is compared with the target CAD geometry and the forming results can be forecasted.

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.

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.

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.

scholarly journals Influence of tool path strategies on the residual stress development in single point incremental forming

2019 ◽  
Vol 29 ◽  
pp. 53-58 ◽  
Author(s):  
Fabian Maaß ◽  
Marlon Hahn ◽  
Mateus Dobecki ◽  
E. Thannhäuser ◽  
A. Erman Tekkaya ◽  
...  
Keyword(s):  
Residual Stress ◽  
Tool Path ◽  
Incremental Forming ◽  
Single Point ◽  
Single Point Incremental Forming ◽  
Stress Development

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.

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