Application Of A New Semi-Empirical Model For Forming Limit Prediction Of Sheet Material Including Superposed Loads Of Bending And Shearing

Journal Article · Tue Jun 15 00:00:00 EDT 2010 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3457654· OSTI ID:21366804

Held, Christian ^[1]; Liewald, Mathias; Schleich, Ralf ^[2]; Sindel, Manfred ^[3]

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1. Hochschul Institute Neckarsulm, Gottlieb-Daimler-Strasse 40, 74172 Neckarsulm (Germany)
2. Institute for Metal Forming Technology, Universitaet Stuttgart, Stuttgart (Germany)
3. AUDI AG, Neckarsulm (Germany)

The use of lightweight materials offers substantial strength and weight advantages in car body design. Unfortunately such kinds of sheet material are more susceptible to wrinkling, spring back and fracture during press shop operations. For characterization of capability of sheet material dedicated to deep drawing processes in the automotive industry, mainly Forming Limit Diagrams (FLD) are used. However, new investigations at the Institute for Metal Forming Technology have shown that High Strength Steel Sheet Material and Aluminum Alloys show increased formability in case of bending loads are superposed to stretching loads. Likewise, by superposing shearing on in plane uniaxial or biaxial tension formability changes because of materials crystallographic texture. Such mixed stress and strain conditions including bending and shearing effects can occur in deep-drawing processes of complex car body parts as well as subsequent forming operations like flanging. But changes in formability cannot be described by using the conventional FLC. Hence, for purpose of improvement of failure prediction in numerical simulation codes significant failure criteria for these strain conditions are missing. Considering such aspects in defining suitable failure criteria which is easy to implement into FEA a new semi-empirical model has been developed considering the effect of bending and shearing in sheet metals formability. This failure criterion consists of the combination of the so called cFLC (combined Forming Limit Curve), which considers superposed bending load conditions and the SFLC (Shear Forming Limit Curve), which again includes the effect of shearing on sheet metal's formability.

• OSTI ID: 21366804
• Journal Information: AIP Conference Proceedings, Vol. 1252, Issue 1; Conference: NUMIFORM 2010: 10. international conference on numerical methods in industrial forming processes dedicated to Professor O. C. Zienkiewicz (1921-2009), Pohang (Korea, Republic of), 13-17 Jun 2010; Other Information: DOI: 10.1063/1.3457654; (c) 2010 American Institute of Physics; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
AUTOMOBILES
AUTOMOTIVE INDUSTRY
BENDING
COMPUTERIZED SIMULATION
CRYSTALLOGRAPHY
DRAWING
FRACTURES
METALS
SHEETS
STEELS
STRAINS
STRESSES
TEXTURE
ALLOYS
CARBON ADDITIONS
DEFORMATION
ELEMENTS
FABRICATION
FAILURES
INDUSTRY
IRON ALLOYS
IRON BASE ALLOYS
MATERIALS WORKING
SIMULATION
TRANSITION ELEMENT ALLOYS
VEHICLES