Force Measurements for Single Point Incremental Forming: An Experimental Study

2005 ◽  
Vol 6-8 ◽  
pp. 441-448 ◽  
Author(s):  
Joost R. Duflou ◽  
Alexander Szekeres ◽  
P. Vanherck
Keyword(s):  
Process Parameters ◽  
Incremental Forming ◽  
Single Point ◽  
Force Measurements ◽  
Test Program ◽  
Forming Process ◽  
Step Size ◽  
Experimental Platform ◽  
Vertical Step ◽  
The Relationship

In this paper an experimental platform capable of measuring forces in process during an incremental forming procedure is described and the results garnered from it are presented. Some of the earliest measurements of forces in incremental forming and the changes induced on the measured load are reported. Using a table type force dynamometer with incremental forming fixture mounted on top, three components of force were measured throughout the forming process. They were found to vary as the parts were made. The reported experimental test program was focused on the influence of three different process parameters on the forming forces: the vertical step size between consecutive contours, the diameter of the tool and the steepness of the part’s wall. For the tested material, analytical results demonstrating the relationship between the respective process parameters and the induced forces are presented in this paper.

scholarly journals Study of Friction and Wear Effects in Aluminum Parts Manufactured via Single Point Incremental Forming Process Using Petroleum and Vegetable Oil-Based Lubricants

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3973
Author(s):  
José M. Diabb Zavala ◽  
Oscar Martínez-Romero ◽  
Alex Elías-Zúñiga ◽  
Héctor Manuel Leija Gutiérrez ◽  
Alejandro Estrada-de la Vega ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Process Parameters ◽  
Friction And Wear ◽  
Incremental Forming ◽  
Single Point ◽  
Single Point Incremental Forming ◽  
Forming Process ◽  
Step Size ◽  
Vertical Step ◽  
Stribeck Curves

This paper focuses on studying how mineral oil, sunflower, soybean, and corn lubricants influence friction and wear effects during the manufacturing of aluminum parts via the single point incremental forming (SPIF) process. To identify how friction, surface roughness, and wear change during the SPIF of aluminum parts, Stribeck curves were plotted as a function of the SPIF process parameters such as vertical step size, wall angle, and tool tip semi-spherical diameter. Furthermore, lubricant effects on the surface of the formed parts are examined by energy dispersive spectroscopy (EDS) and scanning electron microscope (SEM) images, the Alicona optical 3D measurement system, and Fourier-transform infrared spectroscopy (FTIR). Results show that during the SPIF process of the metallic specimens, soybean and corn oils attained the highest friction, along forces, roughness, and wear values. Based on the surface roughness measurements, it can be observed that soybean oil produces the worst surface roughness finish in the direction perpendicular to the tool passes (Ra =1.45 μm) considering a vertical step size of 0.25 mm with a 5 mm tool tip diameter. These findings are confirmed through plotting SPIFed Stribeck curves for the soybean and corn oils that show small hydrodynamic span regime changes for an increasing sample step-size forming process. This article elucidates the effects caused by mineral and vegetable oils on the surface of aluminum parts produced as a function of Single Point Incremental Sheet Forming process parameters.

scholarly journals ANALYSIS OF THE SURFACE QUALITY OF PARTS PROCESSED BY SINGLE POINT INCREMENTAL FORMING

2016 ◽  
Vol 19 (3) ◽  
Author(s):  
CRINA RADU ◽  
EUGEN HERGHELEGIU ◽  
ION CRISTEA ◽  
CAROL SCHNAKOVSZKY
Keyword(s):  
Surface Quality ◽  
Process Parameters ◽  
Incremental Forming ◽  
Single Point ◽  
Single Point Incremental Forming ◽  
Metal Sheets ◽  
Vertical Step ◽  
Tool Diameter ◽  
Aluminium Metal

<p>The aim of the current work was to analyse the influence of the process parameters (tool diameter, size of the vertical step of tool, feed rate and spindle speed) on the quality of the processed surface, expressed in terms of roughness and macrostructure in the case of parts processed by single point incremental forming. The analysis was made on A1050 aluminium metal sheets. The obtained results revealed that the process parameters influence differently the surface quality, the worst influence being exerted by the increase of the vertical step of tool. </p>

Springback Evaluation of Parts Made by Single-Point Incremental Sheet Forming

2011 ◽  
Author(s):  
Paolo Bosetti ◽  
Stefania Bruschi
Keyword(s):  
Process Parameters ◽  
Incremental Forming ◽  
Elastic Recovery ◽  
Single Point ◽  
Industrial Applications ◽  
Geometrical Parameters ◽  
Forming Process ◽  
Part Geometry ◽  
Before And After ◽  
Measuring Machine

One of the major drawbacks of single-point incremental forming process for sheet metal (SPIF) consists in the poor geometrical accuracy of formed parts. This limits the use of SPIF technology and has pushed the development of alternative incremental processes—such as the two-points incremental forming—aimed at improving the forming accuracy. However, these processes require the use of supporting dies and they therefore reduce the competitive advantage of SPIF process. The possibility to compensate for part springback, in order to have the part geometry as close as possible to the nominal one, represents one of the major challenges to make SPIF process suitable for real industrial applications. However, any possible approach in springback compensation must pass through the comprehension of the springback phenomenon. The objective of the paper is to analyze the springback of parts made by SPIF, by evaluating the influence that elastic recovery before and after the part unclamping has on the final part geometry. A SPIF experimental campaign was carried out on a truncated pyramid as case study, by varying both the part geometrical parameters (the wall angle and the height), and the process parameters (the tool step-down size and the feed rate). The material used in this study was the duplex steel DP600 provided in 0.8 mm thick sheets. After forming—but before unclamping—the part geometry was measured by means of of an electronic touch probe mounted on the machine tool-holder, in order to investigate the elastic recovery due to the successive tool laps. After unclamping, the part geometry was measured on a coordinate measuring machine. The influence of geometrical and process parameters was analyzed and the contribution of elastic recovery before and after the part unclamping was assessed.

scholarly journals ANÁLISE EXPERIMENTAL DE ESTAMPABILIDADE DA CHAPA DE AÇO ASTM A653 DURANTE O PROCESSO DE ESTAMPAGEM INCREMENTAL POR PONTO ÚNICO E AVALIAÇÃO DA RUGOSIDADE IMPRESSA NA SUPERFÍCIE CONFORMADA

2021 ◽  
Vol 9 (209) ◽  
pp. 1-51
Author(s):  
Cleiton Ferreira
Keyword(s):  
Incremental Forming ◽  
True Strain ◽  
Single Point ◽  
Roughness Parameter ◽  
Incremental Sheet Forming ◽  
Surface Finishing ◽  
Single Point Incremental Forming ◽  
Step Size ◽  
Vertical Step ◽  
Incremental Step

This study aims to evaluate the behavior of ASTM A653 CS-A G90 steel in the process of Incremental Sheet Forming – ISF, based on the following parameters: diameter of the tool (Dt in mm) and the vertical step size between consecutive contours (∆z in mm). The experiments were based on a variation of the ISF process, called Single Point Incremental Forming - SPIF. In this study, seventeen tests were conducted using a punching tool with diameters (Dt ) of 5, 6 and 8 mm and vertical steps (∆z) of 0.4, 0.6 and 0.8 mm, intending to evaluate the true strain to the ISF process and the surface finishing measured by roughness parameter (Rz). Whereas, for the execution of practical testing, the resources used were a CNCmachining center with three axes, tools for incremental forming and a sheet-press device. As a result, greater depths were achieved using an incremental step of 0.4 mm. In additional tests, it came to attention that the diameter of the tool was also an important parameter when it is desired to increase the formability and greater depths are obtained when using small diameters. It can be observed yet, there is a tendency to increase the roughness parameter Rz when using greater vertical steps ∆z

STUDY ON FORMING FORCES OF PARTS PROCESSED BY SINGLE POINT INCREMENTAL FORMING WITH DUMMY SHEET

2019 ◽  
Vol 14 (3) ◽  
Author(s):  
Vikas Sisodia ◽  
Shailendra Kumar
Keyword(s):  
Process Parameters ◽  
Feed Rate ◽  
Incremental Forming ◽  
Single Point ◽  
Sheet Thickness ◽  
Single Point Incremental Forming ◽  
Forming Force ◽  
Step Size ◽  
Wall Angle ◽  
Influence Of Process Parameters

The present paper describes the experimental investigation on influence of process parameters on maximum forming force in Single Point Incremental Forming (SPIF) process using dummy sheet. Process parameters namely dummy sheet thickness, tool size, step size, wall angle and feed rate are selected. Taguchi L18 orthogonal array is used to design the experiments. From the analysis of variance (ANOVA) dummy sheet thickness, tool size, step size and wall angle are significant process parameters while feed rate is insignificant. It is found that as dummy sheet thickness, tool size, step size and wall angle increase magnitude of peak forming force increases while there is marginal decrease in forming force as feed rate increases. Predictive model is also developed for forming force. Validation tests are performed in order to check the accuracy of developed model. Optimum set of process parameters is also determined to minimize forming force. Experimental results are in good agreement with results predicted by the developed mathematical model.

Single Point Incremental Forming Springback Reduction Using Edge Stiffener

2020 ◽  
Author(s):  
Tyler J. Grimm ◽  
Gowtham V. Parvathy ◽  
Laine Mears
Keyword(s):  
Incremental Forming ◽  
Single Point ◽  
Single Point Incremental Forming ◽  
Back Side ◽  
Forming Process ◽  
Step Size ◽  
Elastic Deformations ◽  
Form Complex ◽  
Large Step ◽  
Large Step Size

Abstract Single point incremental forming (SPIF) is a dieless forming process which uses local deformations to form complex geometries. This is achieved through the use of a typically hemispherical tipped forming tool. Several variations of SPIF have been developed to improve the performance of this process. This includes the use of a partial die which is placed on the back-side of the material. The forming tool is then able to press the material into this partial die. Another method is to utilize a clamping fixture with a periphery that closely matches that of the desired geometry. While both of these methods improve the performance of SPIF, they also require dedicated fixturing. While these modifications still present an advantage over traditional stamping, it is desirable to avoid the use of any geometry-specific equipment. Springback is a significant issue when performing traditional SPIF. Springback can occur in two different ways: local and global. Local springback results from the elastic deformations created outside the region located directly beneath the forming tool. This causes poor accuracy as a result. Compensation methods have been developed to overcome this type of springback but are faced with certain limitations. Global springback refers to the springback experienced once the material is removed from its clamping fixture. This springback is a result of all residual stresses produced during forming. This springback is much more difficult to reduce and often requires annealing the workpiece subsequent to forming. A toolpath approach is explored herein as a method to reduce springback without the use of geometry-specific equipment. The toolpath developed begins at the edge of the clamping fixture, regardless of the geometry shape, and forms the flashing material prior to the desired geometry. By starting the toolpath along the edge of the fixture, elastic deformations are minimized. Additionally, the work hardening produced during this forming acts as a stiffener for the desired geometry, which behaves as a frame which matches the periphery of the desired geometry. This method was experimentally tested for its accuracy improvements when forming a truncated pyramid from 5052 aluminum. The angle of this stiffener, the step size of the stiffener, and the size of the desired geometry were varied. The fixture dimensions were held constant. This method was found to reduce the overall springback of the part and increase the accuracy of the resulting geometry. Furthermore, it was found that a large step size can be used to form the stiffener section of the part. By using a large step size, the time it takes to form this sacrificial region is minimized.

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.

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.

The Effected of Single Point Incremental Forming Process Parameters on the Formed Part Surface Roughness

2014 ◽  
Vol 979 ◽  
pp. 335-338
Author(s):  
Kittiphat Rattanachan ◽  
Chatchapol Chungchoo
Keyword(s):  
Surface Roughness ◽  
Sheet Metal ◽  
Process Parameters ◽  
Feed Rate ◽  
Incremental Forming ◽  
Single Point ◽  
Single Point Incremental Forming ◽  
Tool Rotational Speed ◽  
Forming Process ◽  
Inner Surface

The single point incremental forming process (SPIF) are suited for sheet metal prototyping, because it is a low cost production process that produces sheet metal part without any used of die, and easy to adjust the part’s geometry by change toolpath. But the quality of forming parts is still in doubt. In some applications, such as mould cavity for rapid mould and the medical parts, in this case the inside surface roughness plays an importance role. In this paper, the SPIF process parameters that affected to the inner surface roughness were experimental studied. The investigated parameters are composing of tool feed rate, side overlap, depth step and tool radius. The 2k-p factorial experimental design was used to analyze the interaction between each parameter. The results showed that increasing feed rate and depth step decreased inner surface roughness. Reducing tool rotational speed and feed rate reduced inner surface roughness. So increasing depth step with decreasing side overlap reduced inner surface roughness. The large tool radius and lower side overlap improved inner surface roughness. The large tool radius and higher depth step improved inner surface roughness. And last, reducing tool rotational speed with larger tool radius, the inner surface roughness is decreased.

scholarly journals Surface Finish Analysis in Single Point Incremental Sheet Forming of Rib-Stiffened 2024-T3 and 7075-T6 Alclad Aluminium Alloy Panels

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1640
Author(s):  
Tomasz Trzepieciński ◽  
Andrzej Kubit ◽  
Andrzej Dzierwa ◽  
Bogdan Krasowski ◽  
Wojciech Jurczak
Keyword(s):  
Surface Roughness ◽  
Aluminium Alloy ◽  
Process Parameters ◽  
Rotational Speed ◽  
Single Point ◽  
Core Material ◽  
Tool Rotational Speed ◽  
Roughness Parameters ◽  
Step Size ◽  
Vertical Step

The article presents the results of the analysis of the interactions between the single point incremental forming (SPIF) process parameters and the main roughness parameters of stiffened ribs fabricated in Alclad aluminium alloy panels. EN AW-7075-T6 and EN AW-2024-T3 Alclad aluminium alloy sheets were used as the research material. Panels with longitudinal ribs were produced with different values of incremental vertical step size and tool rotational speed. Alclad is formed of high-purity aluminium surface layers metallurgically bonded to aluminium alloy core material. The quality of the surface roughness and unbroken Alclad are key problems in SPIF of Alclad sheets destined for aerospace applications. The interactions between the SPIF process parameters and the main roughness parameters of the stiffened ribs were determined. The influence of forming parameters on average roughness Sa and the 10-point peak–valley surface roughness Sz was determined using artificial neural networks. The greater the value of the incremental vertical step size, the more prominent the ridges found in the inner surface of stiffened ribs, especially in the case of both Alclad aluminium alloy sheets. The predictive models of ANNs for the Sa and the Sz were characterised by performance measures with R2 values lying between 0.657 and 0.979. A different character of change in surface roughness was found for sheets covered with and not covered with a soft layer of technically pure aluminium. In the case of Alclad sheets, increasing the value of the incremental vertical step size increases the value of the surface roughness parameters Sa and Sz. In the case of the sheets not covered by Alclad, reduction of the tool rotational speed increases the Sz parameter and decreases the Sa parameter. An obvious increase in the Sz parameter was observed with an increase in the incremental vertical step size.

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