ALTERNATIVE NUMERICAL SIMULATION APPROACH FOR OBTAINING FLC/FLD

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.