Forming limit diagram of Al-Cu two-layer metallic sheets considering the Marciniak and Kuczynski theory

2016 ◽  
Vol 232 (5) ◽  
pp. 848-854 ◽  
Author(s):  
Ramin Hashemi ◽  
Ehsan Karajibani
Keyword(s):  
Forming Limit Diagram ◽  
Computational Approach ◽  
Forming Limit ◽  
Experimental Investigations ◽  
System Of Equations ◽  
Forming Limit Diagrams ◽  
Theoretical Predictions ◽  
Experimental Works ◽  
Quasi Newton ◽  
Good Agreement

The aim of this research was to introduce a computational approach for prediction of the forming limit diagram of Al-Cu two-layer metallic sheets. The computational approach was based on the modified Marciniak and Kuczynski theory. In this study, the forming limit diagrams of aluminum–copper two-layer metallic sheets were obtained through the modified Marciniak and Kuczynski theory and experimental investigations. In the present modified Marciniak and Kuczynski theory, there existed four nonlinear equations which were solved simultaneously. The Quasi-Newton Method was applied for a solution to the system of equations. To verify the theoretical predictions, the experimental works were accomplished on the Al-Cu two-layer metallic sheets and a good agreement between the proposed method and experimental works was observed.

scholarly journals Insight into the Influence of Punch Velocity and Thickness on Forming Limit Diagrams of AA 6061 Sheets—Numerical and Experimental Analyses

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2010
Author(s):  
Sasan Sattarpanah Karganroudi ◽  
Shahab Shojaei ◽  
Ramin Hashemi ◽  
Davood Rahmatabadi ◽  
Sahar Jamalian ◽  
...  
Keyword(s):  
Finite Element ◽  
Fe Simulation ◽  
Forming Limit Diagram ◽  
Material Model ◽  
Forming Limit ◽  
Forming Limit Diagrams ◽  
Punch Velocity ◽  
Experimental Analyses ◽  
Insight Into ◽  
Good Agreement

In this article, the forming limit diagram (FLD) for aluminum 6061 sheets of thicknesses of 1 mm and 3 mm was determined numerically and experimentally, considering different punch velocities. The punch velocity was adjusted in the range of 20 mm/min to 200 mm/min during the Nakazima test. A finite element (FE) simulation was carried out by applying the Johnson–Cook material model into the ABAQUSTM FE software. In addition, a comparison between the simulation and the experimental results was made. It was observed that by increasing the punch velocity, the FLD also increased for both thicknesses, but the degree of the improvement was different. Based on these results, we found a good agreement between numerical and experimental analyses (about 10% error). Moreover, by increasing the punch velocity from 20 mm/min to 100 mm/min in 1 mm-thick specimens, the corresponding FLD increased by 3.8%, while for 3 mm-thick specimens, this increase was 5.2%; by increasing the punch velocity from 20 mm/min to 200 mm/min in the 3 mm-thick sheets, the corresponding FLD increased by 9.3%.

Influence of Pre-Forming on the Forming Limit Diagram of Aluminum and Steel Sheets

2007 ◽  
Vol 344 ◽  
pp. 113-118 ◽  
Author(s):  
Massimo Tolazzi ◽  
Marion Merklein
Keyword(s):  
Dual Phase Steel ◽  
Process Analysis ◽  
Forming Limit Diagram ◽  
Forming Limit ◽  
Linear Strain ◽  
Forming Limit Diagrams ◽  
Steel Sheets ◽  
Biaxial Stretching ◽  
Strain Paths

This paper presents a method for the experimental determination of forming limit diagrams under non linear strain paths. The method consists in pre-forming the sheets under two different strain conditions: uniaxial and biaxial, and then stretching the samples, cut out of the preformed sheets, using a Nakajima testing setup. The optical deformation measurement system used for the process analysis (ARAMIS, Company GOM) allows to record and to analyze the strain distribution very precisely with respect to both time and space. As a reference also the FLDs of the investigated grades (the deep drawing steel DC04, the dual phase steel DP450 and the aluminum alloy AA5754) in as-received conditions were determined. The results show as expected an influence of the pre-forming conditions on the forming limit of the materials, with an increased formability in the case of biaxial stretching after uniaxial pre-forming and a reduced formability for uniaxial load after biaxial stretching if compared to the case of linear strain paths. These effects can be observed for all the investigated materials and can be also described in terms of a shifting of the FLD, which is related to the art and magnitude of the pre-deformation.

Analysis of Tube Hydroforming by Means of an Inverse Approach1

2003 ◽  
Vol 125 (2) ◽  
pp. 369-377 ◽  
Author(s):  
Ba Nghiep Nguyen ◽  
Kenneth I. Johnson ◽  
Mohammad A. Khaleel
Keyword(s):  
Tube Hydroforming ◽  
Forming Limit Diagram ◽  
Computational Time ◽  
Forming Limit ◽  
Hydraulic Pressure ◽  
Computational Tool ◽  
Incremental Method ◽  
Inverse Approach ◽  
Initial Geometry ◽  
Good Agreement

This paper presents a computational tool for the analysis of freely hydroformed tubes by means of an inverse approach. The formulation of the inverse method developed by Guo et al. [1] is adopted and extended to the tube hydroforming problems in which the initial geometry is a round tube submitted to hydraulic pressure and axial feed at the tube ends (end-feed). A simple criterion based on a forming limit diagram is used to predict the necking regions in the deformed workpiece. Although the developed computational tool is a stand-alone code, it has been linked to the Marc finite element code for meshing and visualization of results. The application of the inverse approach to tube hydroforming is illustrated through the analyses of the aluminum alloy AA6061-T4 seamless tubes under free hydroforming conditions. The results obtained are in good agreement with those issued from a direct incremental approach. However, the computational time in the inverse procedure is much less than that in the incremental method.

Determination of Forming Limit Diagrams for Thin Foil Materials Based on Scaled Nakajima Test

2015 ◽  
Vol 794 ◽  
pp. 190-198 ◽  
Author(s):  
Stefan Veenaas ◽  
Gerrit Behrens ◽  
Konstantin Kröger ◽  
Frank Vollertsen
Keyword(s):  
Stress State ◽  
Deep Drawing ◽  
Axial Stress ◽  
Forming Limit Diagram ◽  
Thin Foil ◽  
Chromium Steel ◽  
Forming Limit ◽  
Metal Foil ◽  
Forming Limit Diagrams ◽  
Process Understanding

For a better process understanding of micro deep drawing processes and reliable prediction of component failure in FE simulations, it requires the most accurate knowledge of actual material behaviour. However, it is not sufficient to describe material failure for a multi axial stress state in deep drawing using a mechanical parameter as the elongation from tensile test. A forming limit diagram and a forming limit curve are more suited to describe the limit of formability under deep drawing stress state conditions. Methods like hydraulic or pneumatic bulge tests are available to determine forming limit curves even for thin metal foil materials. Nevertheless, using these methods only positive minor strains can be achieved. Especially for a deep drawing process negative minor strains and the left side of a forming limit diagram are more important. Therefore, in this study, experiments based on scaled Nakazima tests were performed to determine complete forming limit diagrams for different foil materials with a thickness range of 20 µm to 25 µm. Scaling the test setup improves the handling of thin specimens. Results with a higher local resolution and the specimens’ size is much closer to the actual size of a micro deep drawn component. Using this testing method forming limit diagrams for the materials Al99.5, E-Cu58, stainless austenitic nickel-chromium steel X5CrNi18-10 (1.4301 / AISI 304), all produced by rolling, and an Al-Zr-foil, produced by a PVD sputtering process, were determined for the micro range.

scholarly journals Viscous Backpressure Forming And Feasibility Study of Hemispherical Aluminum Alloy Parts

2021 ◽  
Author(s):  
Tiejun Gao ◽  
Jiabin Zhang ◽  
Kaixuan Wang
Keyword(s):  
Finite Element Analysis ◽  
Aluminum Alloy ◽  
Forming Limit Diagram ◽  
Loading Path ◽  
Forming Limit ◽  
Distribution Law ◽  
Forming Process ◽  
Element Analysis ◽  
Technical Feasibility ◽  
Forming Limit Diagrams

Abstract Hemispherical aluminum alloy parts are extensively used in modern aerospace and other manufacturing fields. However, wrinkling and cracking easily occur due to the large deformation of the parts, which leads to a complicated forming process. This research proposes a viscous backpressure forming method for hemispherical aluminum alloy parts. The forming limit diagram of LF2 sheet is established through the forming limit experiments. By the combination of finite element analysis and experimental verification, the forming process of the parts under different viscous backpressure and loading path conditions as well as the distribution law of stress-strain and wall thickness of the parts, are obtained. By comparing with the forming limit diagrams, technical feasibility of this forming process is discussed. The research results show that qualified parts can be formed using the viscous backpressure forming method under the conditions of viscous backpressure loading throughout the process with the backpressure at or above 12MPa. This provides a reference for the backpressure forming of hemispherical aluminum alloy parts.

Describing tube formability during pulsating hydroforming using forming limit diagrams

2017 ◽  
Vol 52 (4) ◽  
pp. 249-257 ◽  
Author(s):  
Lianfa Yang ◽  
Daofu Tang ◽  
Yulin He
Keyword(s):  
Deformation Behaviour ◽  
Forming Limit Diagram ◽  
Forming Limit ◽  
Hydraulic Pressure ◽  
Minor Strain ◽  
Steel Tubes ◽  
Periodic Oscillations ◽  
Forming Limit Diagrams ◽  
Uniform Wall ◽  
Forming Limit Curves

Pulsating hydroforming is a novel forming technique that applies pulsating hydraulic pressure to deform tubular materials. Larger expansions and more uniform wall thicknesses in tubes have reportedly been achieved using this technique. However, periodic oscillations of hydraulic pressure acting on the tubes during pulsating hydroforming make the tube deformation behaviour and formability unpredictable. Forming limit diagrams, which consist of two forming limit curves in a major–minor strain coordinate system, are widely used to indicate the formability of sheet materials in plastic deformation. The comparable use of forming limit diagrams to indicate the formability of tubular materials under the pulsating action of hydroforming has not been previously established. In this study, pulsating and non-pulsating hydro-bulging experiments were performed on SS304 stainless steel tubes. Under distinct tension–compression and tension–tension strain states with and without active axial feeding, the forming limit curves for the deformed tubes were constructed based on the experimental data. The effects of various hydraulic pressure pulsating parameters, including pulsating amplitude and frequency, on the forming limit curves were analysed and compared. The experimental results showed that each of the forming limit curves under pulsating hydro-bulging was higher than the forming limit curves under non-pulsating hydro-bulging, thereby confirming the influence of the pulsating parameters. In general, the height of the forming limit curves increased as the pulsating amplitude and frequency increased, largely independent of the tension–compression and tension–tension states. Overall, the results showed that the proposed method for determining the forming limit curves (and the subsequent forming limit diagram) for tubes during pulsating hydro-bulging is feasible.

Experimental Investigation on Formability of Cryorolled and Room Temperature Rolled AA 6061 Sheet Metal with 50% and 75% Thickness Reduction

2014 ◽  
Vol 592-594 ◽  
pp. 302-306 ◽  
Author(s):  
Tinu P. Saju
Keyword(s):  
Experimental Investigation ◽  
Sheet Metal ◽  
Cryogenic Temperature ◽  
Room Temperature ◽  
Forming Limit Diagram ◽  
Thickness Reduction ◽  
Forming Limit ◽  
Forming Limit Diagrams ◽  
Short Annealing ◽  
Clear Idea

This paper deals with the formability of AA 6061 sheet metal. The forming limit diagram of precipitation hardenable Al–Mg–Si alloy namely AA 6061 was evaluated for sheets rolled at two different temperature media namely room temperature and cryogenic temperature. The sheets were subjected to solutionising, rolling either in room temperature or cryogenic temperature with 50% or 75% reduction and short annealing before forming operation. The forming limit diagrams of the rolled sheets were plotted together to obtain a clear idea about their comparative formability.

Constitutive Modelling of Anisotropy, Hardening and Failure of Sheet Metals

2011 ◽  
Vol 473 ◽  
pp. 631-636 ◽  
Author(s):  
Ivaylo N. Vladimirov ◽  
Yalin Kiliclar ◽  
Vivian Tini ◽  
Stefanie Reese
Keyword(s):  
Kinematic Hardening ◽  
Plastic Anisotropy ◽  
Forming Limit Diagram ◽  
Material Model ◽  
Constitutive Modelling ◽  
Forming Limit ◽  
Isotropic Hardening ◽  
Continuum Damage ◽  
Aluminium Sheets ◽  
Good Agreement

The paper discusses the application of a newly developed coupled material model of finite anisotropic multiplicative plasticity and continuum damage to the numerical prediction of the forming limit diagram at fracture (FLDF). The model incorporates Hill-type plastic anisotropy, nonlinear Armstrong-Frederick kinematic hardening and nonlinear isotropic hardening. The numerical examples investigate the simulation of forming limit diagrams at fracture by means of the so-called Nakajima stretching test. Comparisons with test data for aluminium sheets display a good agreement between the finite element results and the experimental data.

Sign in / Sign up

Export Citation Format

Share Document