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| Press tools can now be analysed before manufacture, eliminating the trial and error approach |
Applications - Metal Forming
In addressing the demand for higher quality products in ever shorter time, designers of sheet metal components have turned to computer-based simulation. The goal is to produce tools which form the product 'right first time'. Simulation was initially used to 'trouble shoot' a production problem but is now being used to design and try out the tools before any metal is cast.
LS-DYNA has been used for sheet metal stamping simulation since the late 1980s and can be used to assess a proposed forming process and tool design. Assessment includes not only formability, ie splitting or wrinkling, but also quality, ie impact line location, movement of features, springback and surface conditions such as 'teddy bear's ears'. Complex forming sequences with multiple operations including trimming can be analysed. Simulation allows the designer not only to confirm formability but also to optimise the process, examining different materials, blank shapes, tool loads, lubrication, drawbeads, etc.
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| Three-stage procedure for sheet metal stamping process design |
Forming processes within the scope of LS-DYNA simulation include rigid tool stretch and draw forming (with multiple tool action), sheet and tube hydroforming (including bending operations), flex forming, roll forming and superplastic forming. LS-DYNA simulation can equally be applied to bulk forming problems such as rolling, forging and casting. Forming results can be coupled with structural analysis to see the true response of the component, accounting for thickness, stress and strain variations from forming.
In order to provide a dedicated system for metal forming problems, eta/DYNAFORM has been developed. This system provides comprehensive pre-processing (auto-meshing, tool posistioning, draw bead representation) and post processing (animation, formability plot, forming limit diagram) features in one integrated package, making forming simulation simple and fast.
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| Thickness distribution from LS-DYNA, with prediction compared against measurement |
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Contours of displacement, perfect tool fit
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| The panel on the left was produced from tools designed by simulation; that on the right by traditional methods |
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| Visualisation of 'teddy bear's ears' around a sunroof opening, predicted by Arup software |
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