Locally Applied Direct Electric Current’s Effect on Springback of 2024-T3 Aluminum After Single Point Incremental Forming

2015 ◽  
Author(s):  
Brandt J. Ruszkiewicz ◽  
John T. Roth ◽  
David H. Johnson
Keyword(s):  
Residual Stresses ◽  
Electric Current ◽  
Incremental Forming ◽  
Single Point ◽  
Cnc Machine ◽  
Stress Concentrations ◽  
Forming Process ◽  
Tool Paths ◽  
Forming Technology ◽  
Exact Shape

Incremental forming is a sheet metal forming technology that utilizes a spherical tipped tool and a CNC machine to form a part through a series of spiraling tool paths. Springback is one of the largest concerns for incremental forming since a part can be the exact shape desired after forming until the part is unclamped from its forming fixtures, at which point it will springback due to the residual stresses resident in a part due to the forming process. This paper demonstrates how locally applied electric current can be utilized to reduce the springback due to residual stresses. The tests conducted in this paper demonstrate this concept via incrementally formed truncated-pyramid shapes that were formed from 2024-T3 aluminum. The residual stress concentration locations of the pyramid were determined using FEA. Direct electric current was locally applied to the stress concentrations of the pyramid prior to unclamping. Various current densities, time intervals, and electrical pulse locations were examined to find the ideal conditions for reducing springback for a tested geometry of 2024-T3 aluminum.

scholarly journals Simulation of incremental forming processes of a pyramidal ring made of two materials

2018 ◽  
Vol 19 (3) ◽  
pp. 313
Author(s):  
Masood Ghassabi ◽  
Milad Salimi ◽  
Mohammad Haghpanahi
Keyword(s):  
Feed Rate ◽  
Rotational Speed ◽  
Incremental Forming ◽  
Thickness Distribution ◽  
Single Point ◽  
Dimensional Accuracy ◽  
Cnc Machine ◽  
Forming Force ◽  
Forming Process ◽  
Dimensional Precision

Incremental forming is one of the most well-known forming processes for complex and asymmetric parts. This method uses a CNC machine, simple forming tool, and a die. This study focused on effects of some parameters such as the material, feed rate, pitch, rotational speed and movement strategy of tool on the dimensional precision, forming force, thickness distribution and fracture in the welding area. The results showed that single point incremental forming (SPIF) led to a better thickness distribution with lower tool force, whereas two-point incremental forming led to better dimensional accuracy. Rotational speed does not have any significant impact on the forming process while decreasing the feed rate partially reduced the forming force. According to the results, although dimensional precision in double point incremental forming is better than SPIF, when it comes to the thickness distribution, forming force, and economic issues, SPIF is in favor. The results also showed that by connecting two materials, different parameters for the two materials could be investigated simultaneously in one simulation process.

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.

The Residual Stress State Generated by Single Point Incremental Forming of Aluminum Metal Sheets

2013 ◽  
Vol 371 ◽  
pp. 148-152 ◽  
Author(s):  
Crina Radu ◽  
Eugen Herghelegiu ◽  
Nicolae Catalin Tampu ◽  
Ion Cristea
Keyword(s):  
Residual Stresses ◽  
Incremental Forming ◽  
Single Point ◽  
Hole Drilling ◽  
Single Point Incremental Forming ◽  
Cnc Machine ◽  
Hole Drilling Method ◽  
Residual Stress State ◽  
Metal Sheets ◽  
Drilling Method

Single point incremental forming (SPIF) is a process during which at any moment a very small part of the sample is actually being formed. This progressive highly localised deformation is performed by a simple tool, whose trajectory is numerical controlled by a CNC machine. Since no support for the metal sheet is used during forming, large levels of deformation occur, which in turn, induce highly non-uniform residual stresses that affect the accuracy of the processed parts. The aim of the present paper was to inspect, experimentally and by simulation, the state of the residual stresses induced in SPIFed double frustums of pyramids made by A1050. The hole drilling method was used for the experimental measurements and the LS-Dyna software for simulation.

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.

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.

Incrementally Formed Stiffeners Effect on the Reduction of Springback in 2024-T3 Aluminum After Single Point Incremental Forming

2015 ◽  
Author(s):  
Brandt J. Ruszkiewicz ◽  
Sean S. Dodds ◽  
Zachary C. Reese ◽  
John T. Roth ◽  
Ihab Ragai
Keyword(s):  
Incremental Forming ◽  
Single Point ◽  
Single Point Incremental Forming ◽  
Stress Concentrations ◽  
Forming Process ◽  
Step Size ◽  
New Process ◽  
Geomagic Software ◽  
Truncated Pyramid ◽  
The Ideal

Single Point Incremental Forming (SPIF) is a relatively new process to form sheet metal. SPIF utilizes machines such as CNC’s and mills to form a part by making several spiraled passes, deforming the metal a certain distance, known as the step-size, with each pass. One major issue with this process is global springback. Once the metal is removed from its clamping fixture, the residual stresses that resulted from the forming process cause the material to springback. The purpose of this paper is to demonstrate how incrementally forming a stiffener on the outside of the desired geometry will manipulate the stress concentrations in the metal, and effectively reduce the amount of global springback that occurs after the specimen is unclamped from its fixture. For these tests, stiffeners were formed on the outside of a truncated pyramid; the material used for these test was 2024-T3 aluminum. After the work pieces were removed from their clamping fixtures, the amount of springback that they experienced was examined using Geomagic software to determine the ideal stiffener parameters for reducing global springback for a truncated pyramid in 2024-T3 aluminum.

scholarly journals Adjusting residual stresses by flexible stress superposition in incremental sheet metal forming

2021 ◽  
Author(s):  
Fabian Maaß ◽  
Marlon Hahn ◽  
A. Erman Tekkaya
Keyword(s):  
Residual Stresses ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Incremental Forming ◽  
Single Point ◽  
Forming Process ◽  
Incremental Sheet Metal Forming ◽  
Stress Superposition ◽  
Flexible Die ◽  
Compressive Residual Stresses

AbstractProcess-induced residual stresses significantly influence the mechanical properties of a formed component. A polymer pad is used as a flexible die in two-point incremental forming to induce compressive residual stresses in the component during the forming process. Experimental and numerical results illustrate the influence of compressive stress superposition on the component properties. It is shown that the active support, using a geometry-independent polyurethane die, causes beneficial compressive residual stresses on the tool side compared to the tensile residual stresses induced by the single-point incremental forming process without such a supporting die.

Formability of Tailored Welded Blanks in Single Point Incremental Forming Process

2014 ◽  
Vol 979 ◽  
pp. 339-342 ◽  
Author(s):  
Kittiphat Rattanachan ◽  
K. Sirivedin ◽  
Chatchapol Chungchoo
Keyword(s):  
Laser Welding ◽  
Incremental Forming ◽  
Single Point ◽  
Weld Line ◽  
Welding Process ◽  
Metal Sheet ◽  
Single Point Incremental Forming ◽  
Forming Process ◽  
Forming Technology ◽  
Dieless Forming

This paper is focused on single point incremental forming (SPIF) of a tailored welded blanks (TWBs) that produced by laser welding process. The SPIF process is a new dieless forming technology, which is a fast and economic solution to prototyping a metal sheet product. In the past, the SPIF researches carried out with the homogeneous metal sheet blank, but now a day, the demand of TWBs is still increased especially for an automotive industry. The aim of this research is to study the formability on the weld line of laser welding TWBs (SUS 304 and St 37) by the SPIF process.

Developing a Knowledge Base about the Technological Forces within the Asymmetric Incremental Forming Process

2015 ◽  
Vol 651-653 ◽  
pp. 1115-1121 ◽  
Author(s):  
Melania Tera ◽  
Radu Eugen Breaz ◽  
Octavian Bologa ◽  
Sever Gabriel Racz
Keyword(s):  
Knowledge Base ◽  
Fuzzy Inference ◽  
Incremental Forming ◽  
Single Point ◽  
Feed Speed ◽  
Cnc Machine ◽  
Technological Parameters ◽  
Forming Process ◽  
Inference System ◽  
Sheet Metal Parts

Asymmetric single point incremental forming (ASPIF) has been recognized as a solution with potential in manufacturing small batches or single sheet metal parts. The approach presented in this paper presents the development of a knowledge base regarding the values of the technological force within the ASPIF process and the influence of some technological parameters such as feed, speed of the punch, thickness of the part and step, upon them. The method is based on the use of the information provided by the CNC machine sensors. Relationships between the torques developed by the drive motors on each axes and the technological forces will be set in order to refine the raw information displayed on the machine to a usable form. Finally, using an adaptive neuro-fuzzy inference system the dependence between the value of the technological force and the other parameters has been extracted.

Study of Tool Trajectory in Incremental Forming

2012 ◽  
Vol 472-475 ◽  
pp. 1586-1591 ◽  
Author(s):  
S.H. Wu ◽  
Ana Reis ◽  
F.M. Andrade Pires ◽  
Abel D. Santos ◽  
A. Barata da Rocha
Keyword(s):  
Damage Mechanics ◽  
Tool Path ◽  
Incremental Forming ◽  
Single Point ◽  
Continuum Damage Mechanics ◽  
Work Piece ◽  
Processing Parameter ◽  
Forming Process ◽  
Tool Paths ◽  
Metal Forming Process

Single point incremental forming (SPIF) is an innovative flexible sheet metal forming process which can be used to produce complex shapes from various materials. Due to its flexibility, it attracts a more and more attention in the recent decades. Several studies show that besides the major operating parameters, namely feed rate, tool radius, and forming speed etc., tool path is also an important processing parameter to affect the final forming component. In view of that, the present paper studies the influence of tool paths on the work piece quality by the finite element method coupled with the Continuum Damage Mechanics (CDM) model. The formability of incremental forming in different tool paths is also analyzed.

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