On appropriate Finite Element discretization in simulation of gas-based hot sheet metal forming processes

Abstract

Gaseous medium is being used for sheet metal forming at elevated temperatures, especially for lightweighting purposes. These processes enable forming of high strength alloys of a wide range of thickness due to low material flow stress as well as improved formability. In these processes, the resulting component properties are an interplay of numerous parameters. Instead of cost and time intensive experiments, FEM aids an effective and economic process optimization and enables a better understanding of the influence of process parameters on the component properties. In the current study, the importance of appropriate discretization of the workpiece within a gas-based hot sheet metal forming process is investigated based on a laboratory scale component. AA6010 sheet metal blanks of different thicknesses are studied numerically and experimentally. Simulations with different types of elements are performed and the evolution of process parameters as well as their influence on the final component thickness are analysed. Different element types resulted in noticeable difference in the simulation results and this difference also varies with the initial sheet thickness. Upon further experimental validation, the suitable element type for workpiece discretization is suggested, which enables practitioners to get reliable results via FE simulation of these processes.

Investigation on evolution of microstructure and mechanical properties of heat-treatable 6010-S aluminium alloy during gas-based hot sheet metal forming process

“…The EN AW 6010-S aluminum alloy was previously implemented within the gas-based hot sheet metal forming processes, and its ability to be formed into complex laboratory-scale parts is demonstrated in [1,2]. Moreover, in the authors' previous study [3], the high temperature formability of this alloy is characterized in terms of a forming limit curve, which is further validated within a laboratory scale test.…”

Development of a high-temperature double-layer bulge test for failure prediction in gas-based hot forming of a high-strength aluminium alloy

“…For thickness discretization, nine integration points are taken in shell normal direction. The material properties for deformable bodies are taken from author's previous work [17] and the plasticity modelled using the piecewise_linear_plasticity card in LS-Dyna. The simulations are isothermal at a temperature of 565°C.…”

“…6a, formed via pure gas-based forming process is used to validate the determined FLC. Similar to the setup in [17], this benchmark test consists of hot die and blank holder at 565°C as shown in the Fig. 6b.…”

“…The FE model of cross-die benchmark forming process consisting of rigid tools and deformable blank is setup according to the simulation methods in [17] with Type-2 shell elements. All the boundary conditions in the simulation are modelled as close to the experiment as possible.…”

Implementation of finite element analysis for solving the constraints in forming process of large steel parts

“…Paper [1] study the methods of optimizing sheet metal forming from different views and estimating that the distortion behavior of the sheet metal is the first step to finding the optimal values for these parameters. In work [2], the simulation and analysis are implemented for reducing some defects such as tears, bad formation, and wrinkles. This economic process is significant, and simulation results can offer the best understanding of the influencing parameters on the product properties, and it can be a substitute for intense experiments.…”