A Comparative Investigation on Theoretical Models for Forming Limit Diagram Prediction of Sheet Metals

2021 ◽  
pp. 94-100
Author(s):  
Quoc Tuan Pham ◽  
Trung Nguyen-Thoi ◽  
Duc Toan Nguyen ◽  
Young Suk Kim
Keyword(s):  
Forming Limit Diagram ◽  
Theoretical Models ◽  
Comparative Investigation ◽  
Forming Limit ◽  
Sheet Metals

Integrated Hydraulic Bulge and Forming Limit Testing Method and Apparatus for Sheet Metals

2014 ◽  
Vol 626 ◽  
pp. 171-177 ◽  
Author(s):  
Yan Yo Chen ◽  
Yu Chung Tsai ◽  
Ching Hua Huang
Keyword(s):  
Forming Limit Diagram ◽  
Close Correlation ◽  
Biaxial Stress ◽  
Forming Limit ◽  
Hydraulic Pressure ◽  
Sheet Metals ◽  
Stress Strain ◽  
Testing Method ◽  
Hydraulic Bulge ◽  
Strain Relationship

This paper proposes an integrated hydraulic bulge and forming limit testing method and apparatus for sheet metals. By placing a PU (Polyurethane) plate between molds and uniformly applying hydraulic pressure to sheet metals, a biaxial stress-strain relationship and forming limit diagram (FLD) displaying both left and right sides were acquired using the same apparatus. An uniaxial tension test and traditional drawing test were conducted to compare the results obtained from the proposed hydraulic bulge and forming limit testing methods, respectively. A close correlation between the results of the stress-strain relationship and FLD in both comparisons verified the feasibility and capability of this integrated hydraulic testing method and apparatus for use with sheet metals.

Experimental Determination of Anisotropic Properties and Evaluation of FLD for Sheet Metal Operations

2021 ◽  
Vol 106 ◽  
pp. 39-45
Author(s):  
Araveeti C. Sekhara Reddy ◽  
B. Sandeep ◽  
J. Sandeep Kumar ◽  
B. Sanjanna
Keyword(s):  
Deep Drawing ◽  
Grain Orientation ◽  
Forming Limit Diagram ◽  
Experimental Tests ◽  
Rolling Process ◽  
Forming Limit ◽  
Drawing Process ◽  
Sheet Metals ◽  
Deformation Models

Most of the sheet metals in general exhibit high an-isotropic plasticity behavior due to the ordered grain orientation that occurred during the rolling process. This results in an uneven deformation yield property that tends to develop ears in case of deep-drawing operation. The deep drawing process is used for the production of cup-shaped articles having applications in automobiles, beverages, home appliances etc. It is essential to know the formability of sheet metals for minimisation of test runs and reducingthe defects. Forming Limit Diagram (FLD) is one of the methods for assessment of formability of sheetmetals. This paper describes various deformation models, yielding and an-isotropic properties and itsdetermination. Through experimental tests, FLD constructed for aluminium alloy AA6111 sheet metalhaving 0.9 mm thickness.

Investigations on Influence of Geometric Parameters in Drawing of Perforated Sheet Metals

2016 ◽  
Vol 852 ◽  
pp. 229-235 ◽  
Author(s):  
G. Venkatachalam ◽  
J. Nishanth ◽  
M. Mukesh ◽  
D.S. Pavan Kumar
Keyword(s):  
Sheet Metal ◽  
Software Package ◽  
Parametric Analysis ◽  
Forming Limit Diagram ◽  
Simulation Software ◽  
Geometric Parameters ◽  
Forming Limit ◽  
Sheet Metals ◽  
Open Area ◽  
Perforated Sheet

Forming Limit Diagram (FLD) is a resourceful tool to study the formability of sheet metals. Research on the formability of Perforated Sheet Metal is growing over the years as perforated sheet metal finds its applications in various fields. But finding FLD of perforated sheet metals is complex due to the presence of holes. Also, the hole size, shape and pattern, ligament ratio, thickness of the blank, percentage of open area influence the formability of a perforated sheet metal.In the present scenario, various simulation softwares have made the process of plotting FLD much easier, saving time and money. This paper is an attempt to predict the formability of mild steel perforated sheet metal through simulation software package LS Dyna. Also, Parametric analysis is performed to determine the influence of geometric parameters on the drawability of the perforated sheet metal.

Prediction of Forming Limit Diagram Based on Damage Coupled Kinematic-Isotropic Hardening Model Under Nonproportional Loading

2002 ◽  
Vol 124 (2) ◽  
pp. 259-265 ◽  
Author(s):  
C. L. Chow ◽  
X. J. Yang ◽  
E. Chu
Keyword(s):  
Damage Mechanics ◽  
Kinematic Hardening ◽  
Forming Limit Diagram ◽  
Forming Limit ◽  
Isotropic Hardening ◽  
Strain History ◽  
Sheet Metals ◽  
Nonproportional Loading ◽  
Localized Necking ◽  
Theory Of Damage

Based on the theory of damage mechanics, an anisotropic damage coupled mixed isotropic-kinematic hardening plastic model for the prediction of forming limit diagram (FLD) is developed. The model includes the formulation of nonlinear anisotropic kinematic hardening. For the prediction of limit strains under nonproportional loading, a damage criterion for localized necking of sheet metals subjected to complex strain history is proposed. The model is employed to predict the FLDs of AL6111-T4 alloy. The predicted results agree well with those determined experimentally.

scholarly journals Comparative Investigation of the Experimental Determination of AA5086 FLCs under Different Necking Criteria

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3685
Author(s):  
Xiangrui Kong ◽  
Xingrong Chu ◽  
Chongqian Chen ◽  
Yangang Wang ◽  
Peixing Liu ◽  
...  
Keyword(s):  
Forming Limit Diagram ◽  
Comparative Investigation ◽  
Forming Limit ◽  
Forming Limit Curve ◽  
Localized Necking ◽  
Marciniak Test ◽  
Height Change ◽  
Comparative Results ◽  
Nakajima Test

The construction of a forming limit diagram (FLD) is a conventional approach to obtain limit strains and to evaluate the formability of sheet metal. Appropriate necking criteria should be applied to determine the forming limit curve (FLC) accurately. In recent years, deep research on the determination of the FLC has been carried out; meanwhile, several necking criteria have been proposed. However, the application of inappropriate necking criteria would cause deviations when determining FLCs. In this study, both Marciniak and Nakajima tests were carried out on the AA5086 aluminum sheet to make a comparative investigation of different necking criteria in the determination of FLCs. In the Marciniak test, four existing necking criteria were chosen to construct FLCs, and analyzed in detail. The well-performed time dependent and position dependent methods were selected for the Nakajima test. Meanwhile, the modified Wang method based on the height change of the adjacent points was proposed. The comparative results showed that the time and position dependent methods were relatively conservative in both experiments, while the modified Wang method could identify the onset of localized necking more accurately.

A new tensile test on notched specimens to assess the forming limit diagram of sheet metals

1992 ◽  
Vol 32 (1-2) ◽  
pp. 279-288 ◽  
Author(s):  
D. Priadi ◽  
C. Magny ◽  
E. Massoni ◽  
C. Levaillant ◽  
L. Penazzi
Keyword(s):  
Tensile Test ◽  
Forming Limit Diagram ◽  
Forming Limit ◽  
Sheet Metals ◽  
Notched Specimens
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