scholarly journals Force Prediction for Incremental Forming of Polymer Sheets

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1597 ◽  
Author(s):  
Gustavo Medina-Sanchez ◽  
Alberto Garcia-Collado ◽  
Diego Carou ◽  
Rubén Dorado-Vicente
Keyword(s):  
Numerical Model ◽  
Specific Energy ◽  
Incremental Forming ◽  
Low Cost ◽  
Single Point ◽  
Experimental Tests ◽  
Element Model ◽  
Forming Force ◽  
Polymer Sheets ◽  
Metal Sheets

Incremental sheet forming (ISF) is gaining attention as a low cost prototyping and small batch production solution to obtain 3D components. In ISF, the forming force is key to define an adequate setup, avoiding damage and reducing wear, as well as to determine the energy consumption and the final shape of the part. Although there are several analytical, experimental and numerical approaches to estimate the axial forming force for metal sheets, further efforts must be done to extend the study to polymers. This work presents two procedures for predicting axial force in Single Point Incremental Forming (SPIF) of polymer sheets. Particularly, a numerical model based on the Finite Element Model (FEM), which considers a hyperelastic-plastic constitutive equation, and a simple semi-analytical model that extends the known specific energy concept used in machining. A set of experimental tests was used to validate the numerical model, and to determine the specific energy for two polymer sheets of polycarbonate (PC) and polyvinyl chloride (PVC). The approaches provide results in good agreement with additional real examples. Moreover, the numerical model is useful for accurately predicting temperature and thickness.

scholarly journals Application of the Finite Element Method to the Incremental Forming of Polymer Sheets: The Thermomechanical Coupled Model and Experimental Validations

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1715
Author(s):  
A. García-Collado ◽  
Gustavo Medina-Sanchez ◽  
Munish Kumar Gupta ◽  
R. Dorado-Vicente
Keyword(s):  
Finite Element ◽  
Numerical Solutions ◽  
Incremental Forming ◽  
Low Cost ◽  
Single Point ◽  
Approximation Error ◽  
Coupled Model ◽  
Element Model ◽  
Computational Time ◽  
Polymer Sheets

Single Point Incremental Forming (SPIF) is an innovative die-less low-cost forming method. Until now, there have not been viable numerical solutions regarding computational time and accuracy for the incremental forming of polymers. Unlike other numerical approaches, this novel work describes a coupled thermomechanical finite element model that simulates the SPIF of polymer sheets, where a simple elastoplastic constitutive equation rules the mechanical behavior. The resulting simulation attains a commitment between time and accuracy in the prediction of forming forces, generated and transmitted heat, as well as final part dimensions. An experimental test with default process parameters was used to determine an adequate numerical configuration (element type, mesh resolution, and material model). Finally, compared to a set of experimental tests with different thermoplastics, the proposed model, which does not consider complex rheological material models, shows a good agreement with an approximation error of less than 11% in the vertical forming force prediction.

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.

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>

Incremental Roller-Flanging of Thick Metal Sheets

2021 ◽  
Vol 883 ◽  
pp. 209-216
Author(s):  
Andrea Ghiotti ◽  
Benvenuto Mattia del Tito ◽  
Enrico Simonetto ◽  
Stefania Bruschi ◽  
Stefano Filippi
Keyword(s):  
Metal Forming ◽  
Incremental Forming ◽  
Single Point ◽  
Metal Sheet ◽  
High Tech ◽  
Economic Competitiveness ◽  
Sheet Surface ◽  
Large Size ◽  
Metal Sheets ◽  
Innovative Concept

Metal forming industry is frequently characterized by the demand of small-batch productions to manufacture highly customized products. Apart from the accuracy that is mandatory in high-tech applications, one of the main requirements remains the economic competitiveness that becomes critical in the case of the deformation of thick metal sheets due to the relevant forming loads and the large size of the machines that are required to perform such processes. These problems are partially solved by using incremental forming approaches, in which the deformation is gradually performed by the use of one (single point) or two (double-sided) tools that are usually made to slide on the metal sheet surface while they impose the desired deformation. The paper aims at introducing an innovative concept of incremental forming machine to perform double-sided incremental bends, specifically developed for thick metal sheets. The increased flexibility and the possibility to manufacture sound parts with reduced bending forces are shown and discussed.

A Dynamic Model for KUKA KR6 in SPIF Processes

2019 ◽  
Vol 957 ◽  
pp. 156-166 ◽  
Author(s):  
Mihai Crenganis ◽  
Akos Csiszar
Keyword(s):  
Dynamic Model ◽  
Model Validation ◽  
Incremental Forming ◽  
Industrial Robot ◽  
Single Point ◽  
Single Point Incremental Forming ◽  
Plastic Deformations ◽  
Metal Parts ◽  
Steel Sheets ◽  
Metal Sheets

The paper presents the development of a dynamic model for the KUKA KR6 robot during single point incremental forming (SPIF) of metal sheets. The dynamic model of the KUKA KR6 robot is created in MATLAB®-SimMechanics. This dynamic model is necessary to verify that the mechanical structure of this low payload industrial robot of 36 Kg capacity can withstand some specific forces in incremental forming of some low plasticity alloys like Ti6Al4V. In the Centre of Studies and Research for Plastic Deformations of "Lucian Blaga" University of Sibiu, different attempts on single point incremental forming of thin metal sheets have been carried out and some of the studies are based on SPIF using the KUKA KR6-2 industrial robot. Nevertheless, the previous experimental attempts using the KUKA KR 6-2 robot in SPIF processes were realised only on 0.4 mm thick DC04 steel sheets. This material has very good deformability properties and the forces during the process are relatively small. After the dynamic model validation some specific circular trajectories are imposed and the forces that can appear during SPIF process for Ti6Al4V alloy sheets are taken into consideration. After forces analysis, it was concluded that the KUKA KR6 robot can be used in single point incremental forming processes for metal parts requiring greater forming forces.

A Research of the Precision of Titanium Sheet Formed by Hot Incremental Sheet Forming Method

2017 ◽  
Vol 749 ◽  
pp. 154-160
Author(s):  
Khanh Dien Le ◽  
Tan Hung Nguyen ◽  
Ngoc Huy Tran ◽  
Thanh Son Le ◽  
Huy Bich Nguyen ◽  
...  
Keyword(s):  
Empirical Process ◽  
Incremental Forming ◽  
New Technology ◽  
Single Point ◽  
Metal Sheet ◽  
Forming Process ◽  
Titanium Sheet ◽  
Metal Sheets ◽  
Experimental Process ◽  
Forming Angle

Single Point Incremental Forming (SPIF) is a recent technology of forming sheet in several decades. Nowadays, SPIF technology is still continued to be studied, applied and ameliorated in sheet manufacturing in industry. However one of the difficulties of the technology is the forming angle is still small (smaller than 800 according the properties of metal sheets). This paper recommends a measure of increasing the plasticity of the sheet by heating in time of forming by SPIF technology. Naturally, the plasticity of metal sheet increases by the temperature of the material in forming process with its limitation and constraint. The paper represents the effect of heating metal sheet through the empirical process of SPIF technology directed by the design of experiment (DOE). The analyses of the results of experimental process is applied to show the effect of heating to the precision of Titanium sheet. Finally, some private opinions about the heating in SPIF are also mentioned as a very tiny contribution of the research for the new technology.

Heat Assisted Single Point Incremental Forming of Polymer Sheets

2016 ◽  
Author(s):  
Shubhamkar Kulkarni ◽  
Vijay Sarthy Mysore Sreedhara ◽  
Gregory Mocko
Keyword(s):  
Room Temperature ◽  
Incremental Forming ◽  
Single Point ◽  
Future Research ◽  
Single Point Incremental Forming ◽  
Thermoplastic Polymer ◽  
Localized Deformation ◽  
Hot Air ◽  
Polymer Sheets ◽  
Complex Shapes

The objective of this research is to study the improvement in the formability of thermoplastics using heat assisted single point incremental forming. Single point incremental forming is a production process for forming sheet materials without the use of dedicated tooling (dies/molds). The process is an alternative to thermoforming for low volume forming of sheets. It involves forming the final shape through a series of localized incremental deformations. It has been observed that heat assisted techniques have shown an improvement in the formability limits for sheet metals. In this research, this concept has been tested for improving the formability of polymer sheets. Hot air us used to increase the temperature within a localized region in front of the tool. A single point incremental forming device is modified through the development of a specialized tool holder and nozzle which heats the polymer sheet to temperatures higher than the room temperature but below the glass transition temperature of the polymer and applies the forming loads. The results from the experiments are summarized as: i) the formability angle increases of polystyrene from 27 degrees to 46 degrees when comparing room temperature forming to forming at an elevated temperature (170°F–180 °F), ii) a reduction in the forces needed for forming is observed qualitatively, and iii) the surface finish on the formed parts do not show visible change. This demonstrates promise of manufacturing complex shapes from thermoplastic polymer sheets using heat assisted incremental forming. Future research includes 1) simulating the localized deformation of the material to enable process planning, 2) quantifying the forming forces and heat control of the system, and 3) exploring the manufacturing technique to other materials.

Thickness Distribution and Forming Strategy Analysis for Two Point Incremental Forming with a Male Die

2011 ◽  
Vol 337 ◽  
pp. 452-455 ◽  
Author(s):  
Zhao Bing Liu ◽  
Paul Meehan ◽  
Paul Bellette
Keyword(s):  
Incremental Forming ◽  
Low Cost ◽  
Thickness Distribution ◽  
Single Point ◽  
Three Dimensional ◽  
Dimensional Accuracy ◽  
Strategy Analysis ◽  
Multi Stage ◽  
Analytical Perspective ◽  
Forming Strategy

Incremental Sheet Forming (ISF) is a promising sheet-metal-forming technology which is drawing more and more researchers’ attention due to its flexibility of manufacturing three-dimensional products at a relatively low cost for rapid prototyping and small-batch production. This paper is focused on the thickness distribution and the forming strategy analysis for two point incremental forming with a male die. The analyzed benchmark is half a torus which is generated by revolving a semi-circle. Such a part is hardly able to be formed by single point incremental forming because its slope varies from 0 degree to 90 degrees. In terms of the varying slope, the variant of sine’s law is derived to give an approximate prediction of the thickness distribution from an analytical perspective. In addition, a multi-stage forming strategy is proposed in order to form the part successfully. In particular, a keying operation is implemented carefully in order to avoid twist phenomenon and achieve good dimensional accuracy.

Effect of Incremental Depth and Part Shape on Failure Modes in Single Point Incremental Forming of Polymers

2015 ◽  
Author(s):  
Mohammad Ali Davarpanah ◽  
Rajiv Malhotra
Keyword(s):  
Failure Modes ◽  
Incremental Forming ◽  
Single Point ◽  
Rate Of Change ◽  
Single Point Incremental Forming ◽  
Wall Angle ◽  
Cold Forming ◽  
Modes Of Failure ◽  
Polymer Sheets ◽  
Significant Research

Single Point Incremental Forming (SPIF) has received considerable attention recently due to advantages such as part-shape-independent tooling, higher formability and higher process flexibility as compared to conventional forming. While significant research has been performed on SPIF of metals, recent work has also shown the feasibility of using SPIF for cold-forming of thermoplastic polymer sheets. However, the effects of incremental depth and part shape on the modes of failure during polymer SPIF have rarely been investigated. This paper examines the effects of part shape and incremental depth on the formability and failure modes in polymer SPIF. It is shown that greater incremental depths result in greater formability in polymer SPIF. Furthermore, it is shown that increasing the rate of change of the wall angle with the Z depth of the part increases the maximum formability achievable using a given incremental depth. At the same time, it is observed that this dual advantage of greater formability and reduced forming time, possible with higher incremental depths, is limited by the occurrence of sheet wrinkling when the incremental depth becomes too high. Additionally, the dependence of sheet wrinkling on the overall shape of the part being formed is also shown.

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