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.

Studies of Size Effect on the Formability of a Domed Part in Incremental Forming

2008 ◽  
Author(s):  
Y. Huang ◽  
J. Cao ◽  
S. Smith ◽  
B. Woody ◽  
J. Ziegert ◽  
...  
Keyword(s):  
Size Effect ◽  
Fracture Criterion ◽  
Incremental Forming ◽  
Single Point ◽  
Sheet Thickness ◽  
Fracture Initiation ◽  
Initiation Site ◽  
Forming Limit ◽  
Sheet Formability ◽  
Tool Diameter

The failure strain level in a single point incremental forming (SPIF) process is found to be much higher than that in the traditional stamping process. Based on the assumption that forming limits in SPIF are dominated by fracture failure, the Oyane ductile fracture criterion is introduced in this paper to predict the fracture initiation site, and hence the forming limit, given the stress and strain values obtained from finite element simulations. The predicted results compare well with those obtained from the SPIF experiments. Furthermore, this fracture criterion is used to study the size effects in SPIF. Analytical equations are derived to comprehensively consider the effects of design and process parameters on sheet formability including sheet thickness, tool diameter, and incremental depth. Previously published experimental data is used to verify the feasibility of the proposed size effect equation.

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.

Prediction of Forming Limit in Single Point Incremental Forming With the Ductile Fracture Criterion

2007 ◽  
Author(s):  
Y. Huang ◽  
Y. J. Wang ◽  
J. Cao ◽  
M. Li
Keyword(s):  
Ductile Fracture ◽  
Fracture Criterion ◽  
Incremental Forming ◽  
Single Point ◽  
Forming Limit Diagram ◽  
Theoretical Work ◽  
Negative Slope ◽  
Forming Limit ◽  
Single Point Incremental Forming ◽  
Ductile Fracture Criterion

Many experiments have been conducted to investigate the forming limit in single point incremental forming (SPIF). The forming limit curve (FLC) generated from these experiments follows a linear line with a negative slope in the positive minor strain side of the forming limit diagram (FLD). It is also found that, in general, for the same material subjected to the SPIF process, the failure strain level greatly exceeds the traditional FLC based on theories of the plastic instability [Iseki and Kumon, 1994]. Currently, no theoretical work or no criterion was proposed to predict this FLC in the SPIF. In this paper, the criterion for the ductile fracture [Oyane, 1980] is introduced to try to predict the forming limit of the material in the SPIF. Based on the calculated stress and strain from the finite element simulation and the ductile fracture criterion, the fracture initiation site and the forming limit are predicted. The predicted results are compared with that from the SPIF experiment to verify the feasibility of the proposed method.

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.

Formability Analysis of AA6061 Sheet in T6 Condition

2015 ◽  
Vol 766-767 ◽  
pp. 416-421
Author(s):  
S. Vijayananth ◽  
V. Jayaseelan ◽  
G. Shivasubbramanian
Keyword(s):  
Experimental Method ◽  
Forming Limit Diagram ◽  
Forming Limit ◽  
Ansys Software ◽  
Limit Curve ◽  
High Corrosion Resistance ◽  
Forming Limit Curve ◽  
Drawing Test ◽  
Deep Drawing Test ◽  
Alloy 6061

Formability of a material is defined as its ability to deform into desired shape without being fracture. There will always be a need for formability tests, a larger number of tests have been used in an effort to measure the formability of sheet materials. Aluminium Alloy 6061 is a magnesium and silicon alloy of aluminium. It is also called as marine material as it has high corrosion resistance to seawater. In this paper Formability test of AA6061 sheet is done by Forming Limit Diagram (FLD) Analysis. FLD or Forming Limit Curve (FLC) for the forming processes of AA6061 sheets is obtained by Experimental method and FEM. Experimental method involves Deep drawing test of the sheet and ANSYS software is used for FEM.

Experimental and Numerical Analysis of Forming Limits in CNC Incremental Sheet Forming

2007 ◽  
Vol 344 ◽  
pp. 511-518 ◽  
Author(s):  
Markus Bambach ◽  
M. Todorova ◽  
Gerhard Hirt
Keyword(s):  
Sheet Metal ◽  
Sheet Forming ◽  
Incremental Sheet Forming ◽  
Negative Slope ◽  
Evaluation Procedure ◽  
Forming Limit ◽  
Limit Curve ◽  
Forming Limit Curve ◽  
Forming Limits ◽  
Straight Line

Asymmetric incremental sheet forming (AISF) is a relatively new manufacturing process for the production of low volumes of sheet metal parts. Forming is accomplished by the CNC controlled movements of a simple ball-headed tool that follows a 3D trajectory to gradually shape the sheet metal blank. Due to the local plastic deformation under the tool, there is almost no draw-in from the flange region to avoid thinning in the forming zone. As a consequence, sheet thinning limits the amount of bearable deformation, and thus the range of possible applications. Much attention has been given to the maximum strains that can be attained in AISF. Several authors have found that the forming limits are considerably higher than those obtained using a Nakazima test and that the forming limit curve is approximately a straight line (mostly having a slope of -1) in the stretching region of the FLD. Based on these findings they conclude that the “conventional” forming limit curves cannot be used for AISF and propose dedicated tests to record forming limit diagrams for AISF. Up to now, there is no standardised test and no evaluation procedure for the determination of FLCs for AISF. In the present paper, we start with an analysis of the range of strain states and strain paths that are covered by the various tests that can be found in the literature. This is accomplished by means of on-line deformation measurements using a stereovision system. From these measurements, necking and fracture limits are derived. It is found that the fracture limits can be described consistently by a straight line with negative slope. The necking limits seem to be highly dependent on the test shapes and forming parameters. It is concluded that standardisation in both testing conditions and the evaluation procedures is necessary, and that a forming limit curve does not seem to be an appropriate tool to predict the feasibility of a given part design.

scholarly journals Forming Limit Research of 5182 Aluminum Alloy Sheet Based on Lou-2013 Ductile Fracture Criterion

2019 ◽  
Vol 55 (16) ◽  
pp. 47 ◽  
Author(s):  
YANG Zhuoyun ◽  
ZHAO Changcai ◽  
DONG Guojiang ◽  
CHEN Guang ◽  
ZHU Liangjin ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Ductile Fracture ◽  
Fracture Criterion ◽  
Alloy Sheet ◽  
Forming Limit ◽  
Aluminum Alloy Sheet ◽  
Ductile Fracture Criterion

Visual method for measuring forming limit curve of pliable composite film

2021 ◽  
Vol 0 (0) ◽  
pp. 1-12
Author(s):  
CHEN Ren-hong ◽  
◽  
◽  
LIANG Jin ◽  
YE Mei-tu ◽  
...  
Keyword(s):  
Composite Film ◽  
Forming Limit ◽  
Limit Curve ◽  
Forming Limit Curve ◽  
Visual Method
Sign in / Sign up

Export Citation Format

Share Document