ALTERNATIVE NUMERICAL SIMULATION APPROACH FOR OBTAINING FLC/FLD

Year 2023, , 1 - 9, 15.06.2023

Serap Dikmenli

https://doi.org/10.55696/ejset.1212311

Cited By: 1

Abstract

To be able to predict the forming behavior of sheet metal parts by simulation, it is necessary to determine the FLD1 (Forming Limit Diagram) curves of the sheet material that is subjected to bending, hemming, deep drawing, progressive forming, embossing, hydro-forming processes. To determine such curves, the usual practice is to carry out a series of experiments that need to be repeated many times, and therefore it takes a long time to finalize them [1], [2], [3], [4], [5], [6]. Not to mention undertaken experiments are very detailed and need tedious and careful work has to be done such as screen printing on the material and doing simultaneous optical measurements during the experiments. Indeed, a fully equipped laboratory and qualified lab personnel are required for such experiments which may not be easily found. When it's found, there is usually six months to a year, queue to conduct such experiments.
Because of these difficulties, many academic institutions and manufacturing sites develop their in-house test equipment if funding is available. If not, it is dependent on research whether it comes to an end or whether it can continue without it.
An alternative method developed for extracting FLD/FLC curves is using today’s state-of-the-art simulation technology. This method requires two main inputs;
a) Tensile test of the material
b) An explicit solver
The scope of this paper is to detail this method such that the findings in this document can be reproduced when the mentioned requirements are satisfied. Therefore, all data used in charts, a high-resolution image, and a sample Abaqus input file are provided as supplemental data [7].
The results from the simulations of FLD/FLC were compared to published literature [13] [14] to confirm their compliance with experiments. The comparison showed good results and demonstrates that expensive and time-consuming FLD/FLC experiments are not necessary when the mentioned requirements are met.

Keywords

FLD, FLC, Sheet Metal, Forming, Bending, Hemming, Forming Limit Diagram, Forming Limit Curve

Project Number

17.117

References

• P.E. Smith; D. Lee, Determination of Forming Limits for Aluminum Alloys, SAE Technical Paper 982375, 1998
• ISO 12004-1, Metallic material - Sheet and Strip - Determination of forming-limit curves. Part 1: Measurement and application of forming limit diagrams in press shop, 2008.
• ISO 12004-2, Metallic material - Sheet and Strip - Determination of forming-limit curves. Part 2: Determination of forming-limit curves in the laboratory, 2008.
• ASTM E2218-02, 2008, "Standard Test Method for Determining Forming Limit Curves," Annual Book of ASTM Standards, Vol. 03.01, ASTM International, West Conshohocken, PA.
• ASTM E643, Standard Test Method for Ball Punch Deformation of Metallic Sheet Material, 2009.
• ISO 20482, Metallic Materials - Sheet and strip - Erichsen cupping test, 2003.
• S. Dikmenli, Alternative Numerical Simulation Approach for Obtaining FLC/FLD - Supplementary Data (https://data.mendeley.com/datasets/4wg9nkz8b6), Mendeley Data, V1, doi: 10.17632/4wg9nkz8b6.1, 2022
• ISO 6892-1, Metallic materials — Tensile testing. Part 1: Method of test at room temperature, 2019
• Mechanical Properties of Materials (https://mechanicalc.com/reference/mechanical-properties-of-materials#stress-strain-approx), MechaniCalc Inc., November, 23th 2022.
• S. Korkut, Serdar, Gerilme-Gerinim (Stress-Strain) Eğrisi (https://www.serdarkorkut.com/2017/05/09/gerilme-gerinim-stress-strain-egrisi/), November, 23th 2022.
• W. Yuan, M. Wan, X. Wu, “Prediction of Forming Limit Curves for 2021 Aluminum Alloy”, Procedia Engineering, 207, 544-549, 2017.
• D. Lumelskyj, J. Rojek, L. Lazarescu, D. Banabic, “Determination of forming limit curve by finite element method Simulations”, Procedia Manufacturing, 27, 78-82, 2019
• Bake hardening steels (https://automotive.arcelormittal.com/products/flat/HYTSS/BH), ArcelorMittal, November, 23th 2022.
• F. Djavanroodi, A. Derogar, “Experimental and numerical evaluation of forming limit diagram for Ti6Al4V titanium and Al6061-T6 aluminum alloys sheets”, Materials and Design, vol 31, pp 4866–4875, 2010.