Page 27 - MetalForming Magazine June/July 2022 80th Anniversary Issue

Cutting Edge
Initial Embossed 90 mm Blank Blank before
BDC
60 mm before BDC
30 mm before BDC
15 mm before BDC
5 mm BDC After before Trimming
BDC
Fig. 3—During crash forming, very high wrinkles may appear. At bottom dead center (BDC), the wrinkles are flattened, as are the embossments in some assembly areas; the highest wrinkles are observed around 5 mm before BDC.
es in two commercially available sim- ulation programs. We used an initial rectangular blank cut from 0.5-mm- thick 1050-O aluminum.
During crash forming, very high wrinkles may appear (Fig. 3). At bottom dead center (BDC), the wrinkles are flattened, as are the embossments in some assembly areas; the highest wrin- kles are observed around 5 mm before BDC.
Metal forming simulation can help a designer reduce costs by:
1. Optimizing the initial blank dimensions. If possible, start with a
rectangular blank to save significant capital and operational expenses— made possible by employing shear cut- ting rather than a blanking line.
2. Optimizing the embossment ratio for formability (if customer specifica- tions allow). One also can use the final geometry of the metal forming simu- lation (typically exported as an STL file) and perform thermal simulation to evaluate heat shield performance.
3. Optimizing the forming process. If possible, avoid any pads or blankholders (i.e., employing crash forming) to reduce costs for building
and maintaining the tool. However, scrap rates may be high. Metal forming simulation can help determine the optimum solution. Most of the failure modes explained here (apart from edge cracks, which may require additional material-characterization tests) can be predicted by simulation. Any potential rework on the tool can be performed virtually on the computer screen. MF
Acknowledgments
This study is a joint work with Aksel Muti of TKG Automotive R&D, Bursa, Turkey (www.tkg.com.tr).
24 MetalForming/June/July 2022
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