New Methodologies for the Determination of Precise Forming Limit Curve in Single Point Incremental Forming Process

2010 ◽  
Vol 97-101 ◽  
pp. 126-129 ◽  
Author(s):  
Ghulam Hussain ◽  
Gao Lin ◽  
Nasir Hayat ◽  
Nameem Ullah Dar ◽  
Asif Iqbal
Keyword(s):  
Incremental Forming ◽  
Single Point ◽  
Forming Limit ◽  
Single Point Incremental Forming ◽  
Limit Curve ◽  
Forming Process ◽  
Forming Limit Curve ◽  
Groove Test ◽  
New Methodologies

Straight groove test is a widely-used formability test in Single Point Incremental Forming (SPIF). This test does not cover all the forming aspects of SPIF process, however. In order to ascertain its legitimacy, two new tests covering necessary SPIF aspects are devised. The FLC of an aluminum sheet is determined using the newly proposed and straight groove tests. It is found that the straight groove test shows much lower formability than the new tests. Therefore, the employment of newly devised test(s) is proposed for the determination of precise formability limits.

Experimental Investigation of Single Point Incremental Forming of Aluminum Sheet in Groove Test

2017 ◽  
Vol 867 ◽  
pp. 177-183 ◽  
Author(s):  
Vikrant Sharma ◽  
Ashish Gohil ◽  
Bharat Modi
Keyword(s):  
Experimental Investigation ◽  
Incremental Forming ◽  
Single Point ◽  
Fractional Factorial ◽  
Single Point Incremental Forming ◽  
Forming Process ◽  
Backing Plate ◽  
Groove Test ◽  
Factorial Design Of Experiments ◽  
Tool Diameter

Incremental sheet forming is one of the latest processes in sheet metal forming industry which has drawn attention of various researchers. It has shown improved formability compared to stamping process. Single Point Incremental Forming (SPIF) process requires only hemispherical tool and no die is required hence, it is a die-less forming process. In this paper experimental investigation on SPIF for Aluminium sheet has been presented. A groove test on Vertical Machining Centre has been performed. Factors (Step depth, Blank holder clamping area, Backing plate radius, Program strategy, Feed rate and Tool diameter) affecting the process are identified and experiments are carried out using fractional factorial design of experiments. Effect of the factors on fractured depth, forming time and surface finish have been analyzed using Minitab 17 software.

Study on Forming Behaviour of Friction Stir Welded Blanks During Single Point Incremental Forming (SPIF) Process

2020 ◽  
Author(s):  
Shalin Marathe ◽  
Harit Raval
Keyword(s):  
Friction Stir Welding ◽  
Incremental Forming ◽  
Single Point ◽  
Base Material ◽  
Forming Limit ◽  
Single Point Incremental Forming ◽  
Cnc Milling ◽  
Forming Process ◽  
Friction Stir ◽  
Welding Processes

Abstract The automobile, transportation and shipbuilding industries are aiming at fuel efficient products. In order to enhance the fuel efficiency, the overall weight of the product should be brought down. This requirement has increased the use of material like aluminium and its alloys. But, it is difficult to weld aluminium using conventional welding processes. This problem can be solved by inventions like friction stir welding (FSW) process. During fabrication of product, FSW joints are subjected to many different processes and forming is one of them. During conventional forming, the formability of the welded blanks is found to be lower than the formability of the parent blank involved in it. One of the major reasons for reduction in formability is the global deformation provided on the blank during forming process. In order to improve the formability of homogeneous blanks, Single Point Incremental Forming (SPIF) is found to be giving excellent results. So, in this work formability of the welded blanks is investigated during the SPIF process. Friction Stir Welding is used to fabricate the welded blanks using AA 6061 T6 as base material. Welded blanks are formed in to truncated cone through SPIF process. CNC milling machine is used as SPIF machine tool to perform the experimental work. In order to avoid direct contact between weld seam and forming tool, a dummy sheet was used between them. As responses forming limit curve (FLC), surface roughness, and thinning are investigated. It was found that use of dummy sheet leads to improve the surface finish of the formed blank. The formability of the blank was found less in comparison to the parent metal involved in it. Uneven distribution of mechanical properties in the welded blanks leads to decrease the formability of the welded blanks.

Experimental Study on Residual Formability of Single Point Incrementally Formed Part

2019 ◽  
Author(s):  
Chetan P. Nikhare
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Incremental Forming ◽  
Thickness Distribution ◽  
Single Point ◽  
Forming Limit ◽  
Single Point Incremental Forming ◽  
Forming Process ◽  
Conventional Process

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.

scholarly journals Simulation of the Single Point Incremental Forming of Polyamide and Polyethylene Sheets

2019 ◽  
Vol 290 ◽  
pp. 03014
Author(s):  
Nicolae Alexandru Roşca ◽  
Mihaela Oleksik
Keyword(s):  
Incremental Forming ◽  
True Strain ◽  
Single Point ◽  
Polymeric Materials ◽  
Single Point Incremental Forming ◽  
Forming Process ◽  
Explicit Analysis ◽  
Polyamide 6.6 ◽  
Experimental Researches

The present paper aims the theoretical study, using the finite element method, on the single point incremental forming process of two polymeric materials: polyamide 6.6 and high-density polyethylene. The experimental researches used for the determination of the true stress - true strain curves for two materials are presented, which are necessary for their introduction into the simulation. The explicit analysis is carried out with the Ls-Dyna program and the results of the analysis were focused on the major strain, minor strain, thickness reduction, forces on the process and total energy consumed in the process.

Comparative Study for Springback Prediction on Single Point Incremental Forming Process

2014 ◽  
Vol 622-623 ◽  
pp. 375-381
Author(s):  
Valentin Oleksik ◽  
Adrian Pascu ◽  
Ioan Bondrea ◽  
Eugen Avrigean ◽  
Liviu Rosca
Keyword(s):  
Comparative Study ◽  
Incremental Forming ◽  
Single Point ◽  
Single Point Incremental Forming ◽  
Forming Process ◽  
Machined Surface ◽  
Fully Integrated ◽  
Explicit Dynamic ◽  
Springback Prediction

The present paper proposes a comparative study in order to determine the springback in single point incremental forming process. Using the Ls-Dyna software the process was simulated for one piece in frustum of pyramid shape. In the end of the explicit dynamic analysis, it was run, using the same software, an implicit analysis to determine the springback. For this comparison study we selected four different shell formulations. The results obtained in this simulation were compared with those obtained experimentally for the same part. The experimental research was conducted on a robot and, on the opposite side of the machined surface, an Aramis measuring optical system was placed to allow the online determination of deformations, displacements and thinning of material. Also, using this system, the springback was determined at the end of forming process. The closest values were obtained when using fully integrated formulation with thickness-stretch with 11 integration points on material thickness.

Prediction and Research of Single Point Incremental Forming Limit

2010 ◽  
Vol 97-101 ◽  
pp. 4005-4009
Author(s):  
Lei Li ◽  
Wan Lin Zhou ◽  
Ghulam Hussain
Keyword(s):  
Fracture Criterion ◽  
Incremental Forming ◽  
Single Point ◽  
Fracture Initiation ◽  
Forming Limit ◽  
Ductile Fracture Criterion ◽  
Limit Curve ◽  
Forming Limit Curve ◽  
Strain Data ◽  
Characteristic Stress

Sing point incremental forming (SPIF) limit is much higher than the traditional processes. Currently, there are still no systematic theories and criterions to predict the limit. In this paper, the Oyane ductile fracture criterion is introduced to predict the forming limit of SPIF based on the stress-strain data by the finite element simulations. The predicted fracture initiation sites and the forming limit curve are consistent with the experiment results; further, the forming characteristic, stress state, local temperature are the main reasons of the higher forming limit in SPIF.

A New Workability Criterion for Ductile Metals

1986 ◽  
Vol 108 (3) ◽  
pp. 245-249 ◽  
Author(s):  
V. Vujovic ◽  
A. H. Shabaik
Keyword(s):  
Effective Stress ◽  
Forming Limit ◽  
Limit Curve ◽  
Forming Process ◽  
Forming Limit Curve ◽  
Ductile Metals ◽  
State Of Stress ◽  
Forming Limit Curves ◽  
Hydrostatic Component

The forming limit curves are important aids in determining the extent of deformation a material can be subjected to during a forming process. In this paper a forming limit criterion for bulk metalworking processes, based on the magnitude of the hydrostatic component and the effective stress of the state of stress, is proposed. The determination of the forming limit curve by means of three simple tests, namely, tension, compression, and torsion tests, is presented.

A Fundamental Investigation on the Formability of a Commercially-Pure Titanium Sheet-Metal in the Incremental Forming and Stamping Processes

2007 ◽  
Author(s):  
G. Hussain ◽  
L. Gao ◽  
Wang Hui ◽  
N. U. Dar
Keyword(s):  
Incremental Forming ◽  
Single Point ◽  
Pure Titanium ◽  
Dome Height ◽  
Forming Limit ◽  
Commercially Pure Titanium ◽  
Limit Curve ◽  
Forming Limit Curve ◽  
Commercially Pure ◽  
Cp Ti

In the present study, a basic comparison between the cold formability of a commercially-pure Titanium (CP Ti) sheet in the single-point incremental forming (SPIF) and stamping processes is presented. An attempt was made to evaluate the SPIF formability by employing two tests. In the first test, parts having continuously varying wall angles were formed. While in the second test, parts having fixed wall angles were formed. The stamping formability was determined by conducting the limiting dome height (LDH) test. It is concluded that the forming limit curve (FLC) in SPIF is located much higher than the stamping FLC, even higher than the fracture limit curve in stamping. Moreover, the SPIF formability shows dependence on the test employed.

Comparison of Predicted Forming Limit Curves with Measured Experimental Data on Hot-Dip Zinc-Coated Cold-Rolled Steel by Incremental Forming Process

2019 ◽  
Vol 821 ◽  
pp. 256-262 ◽  
Author(s):  
Ramil Kesvarakul ◽  
Khompee Limpadapun
Keyword(s):  
Experimental Data ◽  
Incremental Forming ◽  
True Strain ◽  
Single Point ◽  
Forming Limit ◽  
Rolled Sheet ◽  
Single Point Incremental Forming ◽  
Forming Process ◽  
Cold Rolled ◽  
Forming Limit Curves

Single Point Incremental Forming (SPIF) is a die-less forming process with advantages of high-flexibility, low-cost and short lead time. The high local strains that are applied to the metal sheet, often exceeding the conventional formability limit. This paper is focused on comparison of predicted forming limit curves with measured experimental data on Hot-Dip Zinc-Coated Cold-Rolled sheet, with 0.20 mm thick is studied in single point incremental forming. Truncated square pyramid and cone are formed to study the formability of blank sheets at room temperature. It was found that both Formulation of plastic instability criteria and Keeler’s formula gives the lowest FLC. FLDs have predicted failures in forming process consistently with the real experiments. The experimentally obtained cracking limit differ from analytical one and empirical one by about 3.398 and 2.135 true strain respectively at FLD0, the corresponding plane strain values.

Formability of AA7075 Sheet in Single Point Incremental Forming

2021 ◽  
Vol 11 (2) ◽  
pp. 40-54
Author(s):  
Gautam Kumar ◽  
Kuntal Maji
Keyword(s):  
Plane Strain ◽  
Strain Path ◽  
Incremental Forming ◽  
Single Point ◽  
Forming Limit ◽  
Single Point Incremental Forming ◽  
Wall Angle ◽  
Groove Test ◽  
Deformation Instability ◽  
Experimental Values

This article presents formability analysis of aluminium alloy 7075 thin sheets in single point incremental forming (SPIF) through prediction of forming limit curve (FLC) and maximum formable wall angle. Deformation instability method based on tool-sheet contact and non-contact zones in incremental forming was used for the prediction of limit strains for plane strain and equi-biaxial stretching strain path. FLC of the material was also determined experimentally, after measuring limit strains for deformed sheet through groove test for the process. Further, maximum forming wall angle of the material was determined for deformed sheet in a square pyramid shape. The theoretical limit strains predicted by deformation instability approach were compared to the experimental values. Theoretically, calculated limit strains were observed to be higher for plane strain path but approximately close for equi-biaxial strain path compared to experimental limit strains. The maximum formable wall was found to be 55˚ for the material in the process.

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