scholarly journals PROCESS SIMULATION AND QUALITY EVALUATION IN INCREMENTAL SHEET FORMING

2011 ◽  
Vol 12 (3) ◽  
Author(s):  
Meftah Hrairi ◽  
Salah B. M. Echrif

Single Point Incremental Forming (SPIF) is a promising sheet-metal-forming process that permits the manufacturing of small to medium-sized batches of complex parts at low cost. It allows metal forming to work in the critical ‘necking-to-tearing' zone which results in a strong thinning before failure if the process is well designed. Moreover, the process is complex due to the number of variables involved. Thus, it is not possible to consider that the process has been well assessed; several remaining aspects need to be clarified. The objective of the present paper is to study some of these aspects, namely, the phenomenon of the wall thickness overstretch along depth and the effect of the tool path on the distribution of the wall thickness using finite element simulations.Abstrak: Pembentukan Tokokan Mata Tunggal (Single Point Incremental Forming (SPIF)) merupakan satu proses pembentukan kepingan logam yang membolehkan pembuatan dalam jumlah yang kecil hingga sederhana, bahagian-bahagian yang kompleks pada kos yang rendah. Jika proses ini direka dengan baik, kaedah ini membolehkan pembentukan logam yang baik terhasil. Jika tidak, semasa peringkat zon kritikal ‘perleheran-ke-pengoyakan' menyebabkan penipisan keterlaluan yang boleh menyebabkan logam tersebut rosak. Tambahan pula, proses ini agak kompleks, kerana ia melibatkan beberapa pemboleh ubah. Maka, walaupun proses ini telah dinilaikan seeloknya; masih terdapat beberapa aspek lain yang perlu diperjelaskan. Objektif kertas ini dibentangkan adalah untuk mengkaji beberapa aspek tertentu, seperti, ketebalan dinding regangan berlebihan di sepanjang kedalaman dan kesan tool path (beberapa siri posisi koordinat untuk menentukan pergerakan alatan memotong ketika operasi memesin) terhadap pengagihan ketebalan dinding menggunakan simulasi unsur terhingga.

2021 ◽  
Vol 343 ◽  
pp. 04007
Author(s):  
Mihai Popp ◽  
Gabriela Rusu ◽  
Sever-Gabriel Racz ◽  
Valentin Oleksik

Single point incremental forming is one of the most intensely researched die-less manufacturing process. This process implies the usage of a CNC equipment or a serial robot which deforms a sheet metal with the help of a relatively simple tool that follows an imposed toolpath. As every cold metal forming process, besides the many given advantages it has also some drawbacks. One big drawback in comparison with other cold metal forming processes is the low accuracy of the deformed parts. The aim of this research is to investigate the sheet metal bending mechanism through finite element method analysis. The results shows that the shape of the retaining rings has a big influence over the final geometrical accuracy of the parts manufactured through single point incremental forming.


2010 ◽  
Vol 129-131 ◽  
pp. 1222-1227 ◽  
Author(s):  
Ghulam Hussain ◽  
Gao Lin ◽  
Nasir Hayat ◽  
Asif Iqbal

Single Point Incremental Forming (SPIF) is a novel sheet metal forming process. The formability (i.e. spif-ability) in this process is determined through Varying Wall Angle Conical Frustum (VWACF) test. In this paper, the effect of variation in the curvature radius, a geometrical parameter of test, on the test results is investigated. A series of VWACF tests with a variety of curvature radii is performed to quantify the said effect. It is found that the spif-ability increases with increasing of curvature radius. However, any variation in the curvature radius does not affect the spif-ability when the normalized curvature radius (i.e. curvature radius/tool radius) becomes higher than 9.


2015 ◽  
Vol 809-810 ◽  
pp. 277-282
Author(s):  
Khalil Ibrahim Abass

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.


2011 ◽  
Vol 264-265 ◽  
pp. 188-193 ◽  
Author(s):  
G. Palumbo ◽  
Marco Brandizzi ◽  
G. Cervelli ◽  
M. Fracchiolla

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.


Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1287
Author(s):  
Fernando Bautista-Monsalve ◽  
Francisco García-Sevilla ◽  
Valentín Miguel ◽  
Jesús Naranjo ◽  
María Carmen Manjabacas

Single point incremental forming (SPIF) is a cheap and flexible sheet metal forming process for rapid manufacturing of complex geometries. Additionally, it is important for engineers to measure the surface finish of work pieces to assess their quality and performance. In this paper, a predictive model based on machine learning and computer vision was developed to estimate arithmetic mean surface roughness (Ra) and maximum peak to valley height (Rz) of Ti6Al4V parts obtained by SPIF. An image database was prepared to train different classification algorithms in accordance with a supervised learning approach. A speeded up robust feature (SURF) detector was used to obtain visual vocabulary so that the classifiers are able to group the photographs into classes. The experimental results indicated that the proposed predictive method shows great potential to determine the surface quality, as classifiers based on a support vector machine with a polynomial kernel are suitable for this purpose.


Author(s):  
Chetan P. Nikhare

Abstract A substantial increase in demand on the sheet metal part usage in aerospace and automotive industries is due to the increase in the sale of these products to ease the transportation. However, due to the increase in fuel prices and further environmental regulation had left no choice but to manufacture more fuel efficient and inexpensive vehicles. These heavy demands force researchers to think outside the box. Many innovative research projects came to replace the conventional sheet metal forming of which single point incremental forming is one of them. SPIF is the emerging die-less sheet metal forming process in which the single point tool incrementally forces any single point of sheet metal at any processing time to undergo plastic deformation. It has several advantages over the conventional process like high process flexibility, elimination of die, complex shape and better formability. Previous literature provides enormous research on formability of metal during this process, process with various metals and hybrid metals, the influence of various process parameter, but residual formability after this process is untouched. Thus, the aim of this paper is to investigate the residual formability of the formed parts using single point incremental forming and then restrike with a conventional tool. The common process parameters of single point incremental forming were varied, and residual formability was studied through the conventional process. The strain and thickness distribution were measured and analyzed. In addition, the forming limit of the part was plotted and compared.


Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4719
Author(s):  
Kyu-Seok Jung ◽  
Jae-Hyeong Yu ◽  
Wan-Jin Chung ◽  
Chang-Whan Lee

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.


2009 ◽  
Vol 410-411 ◽  
pp. 391-400 ◽  
Author(s):  
Aldo Attanasio ◽  
Elisabetta Ceretti ◽  
Antonio Fiorentino ◽  
Luca Mazzoni ◽  
Claudio Giardini

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.


Author(s):  
Rakesh Lingam ◽  
Anirban Bhattacharya ◽  
Javed Asghar ◽  
N. Venkata Reddy

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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