Numerical Investigation of the Tool Load in Joining by Forming of Dissimilar Materials Using Shear-Clinching Technology

Abstract:

Modern developments in the automotive sector are motivated by the objective of lowering the emission of pollutants. In contrast, growing demands for safety and comfort lead to a potential increase of the weight of vehicles. Thus, the consequent use of lightweight design is indispensable. This includes the use of different materials for the construction of car bodies. Because of various material properties, joining of dissimilar materials is challenging and requires often the application of non-thermic processes like riveting or clinching. These processes are limited by the mechanical properties of the joining partners. Especially the increasing use of ultra-high strength alloys, like the hot stamped steel 22MnB5, makes the development of new joining technologies necessary. One of these innovative technologies is shear-clinching. By combining shear-cutting and clinching in one process, this technology produces durable and tight connections of dissimilar materials with high differences regarding strength and formability. In contrast to shear-cutting the die-sided material has no contact with the punch. Since the process of shear-clinching is a combination of cutting and joining using the same tool, the tool loads differ from common shear-cutting. Especially cutting hot stamped steels is a challenge due to their high ultimate strength which leads to high tool loads. Thus, the analysis of the load condition is essential for the dimensioning of durable and wear resistant tools. Hence, the scope of this paper is a numerical investigation of the tool loads during the indirect cutting process and the subsequent step of joining by forming during shear-clinching. Since an experimental investigation of the occurring tool loads in the closed process is not practicable, the finite element method has to be used. Therefore, a damage-based numerical model is set up to enable the coupled simulation of the combined cutting and joining process and the resulting tool loads. This allows the analysis of the loads during the whole process, identifying the influences of materials and sheet thicknesses.

• Periodical: Key Engineering Materials (Volume 767)
• Pages: 397-404
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.767.397
• Online since: April 2018
• Authors: Sebastian Wiesenmayer*, Martin Müller, Peter Dornberger, Daxin Han, Réjane Hörhold, Gerson Meschut, Marion Merklein
• Keywords: Finite Element Method, Joining, Shear-Clinching, Tool

References

[1] J. Varis, Economics of clinched joint compared to riveted joint and example of applying calculations to a volume product, Journal of Materials Processing Technology 172 (2006) 130-138.

DOI: 10.1016/j.jmatprotec.2005.09.009

[2] DVS/EFB-Merkblatt 3420, Clinchen - Überblick, (2012).

[3] Y. Abe, K. Mori, T. Kato, Joining of high strength steel and aluminium alloy sheets by mechanical clinching with dies for control of metal flow, Journal of Material Processing Technology 212 (2012) 884-889.

DOI: 10.1016/j.jmatprotec.2011.11.015

[4] G. Meschut, V. Janzen, T. Olfermann, Innovative and Highly Productive Joining Technologies for Multi-Material Lightweight Car Body Structures, Journal of Materials Engineering and Performance 23 (5) 1515-1523.

DOI: 10.1007/s11665-014-0962-3

[5] S. Busse, M. Merklein, K. Roll, Development of a Mechanical Joining Process for Automotive Body-In-White Production, International Journal of Material Forming 3 (2010) 130-138.

DOI: 10.1007/s12289-010-0953-3

[6] M. Müller, R. Hoerhold, G. Meschut, M. Merklein, Numerische Untersuchung des Werkstoffflusses beim Fügen artungleicher Werkstoffe mittels Schneidclinchen, in A. Brosius, Tagungsband SFU 2016, 2016, pp.158-165.

[7] R. Hörhold, M. Müller, M. Merklein, G. Meschut, Mechanical properties of an innovative shear-clinching technology for ultra-high-strength steel and aluminium in lightweight car body structures, Welding in the World 60 (2016) 3 613-620.

DOI: 10.1007/s40194-016-0313-0

[8] K. Nothaft, Scherschneiden höchstfester Blechwerkstoffe im offenen Schnitt, Dissertation, Munich, (2014).

[9] J. E. Hockett, O. E. Sherby, Large strain deformation of polycrystalline metals at low homologous temperatures, J. Mech. Phys. Solid 23-2 (1975) 87–98.

DOI: 10.1016/0022-5096(75)90018-6

[10] M. Müller, R. Hörhold, G. Meschut, M. Merklein, FE-based study of the cutting operation within joining by forming of dissimilar materials using shear-clinching technology, Applied Mechanics and Materials 794 (2015) 304-311.

DOI: 10.4028/www.scientific.net/amm.794.304

[11] M. G. Cockcroft, D. J. Latham, Ductility and the Workability of Metals, Journal of the Institute of Metals 96 (1968) 33-39.

[12] M. Müller, U. Vierzigmann, R. Hörhold, G. Meschut, M. Merklein, Development of a testing method for the identification of friction coefficients for numerical modeling of the shear-clinching process, Key Engineering Materials 639 (2015) 469-476.

DOI: 10.4028/www.scientific.net/kem.639.469

[13] DIN EN 485-4:1993, Aluminium und Aluminiumlegierungen, Bänder, Bleche und Platte, - Teil 4: Grenzabmaße und Formtoleranzen für kaltgewalzte Erzeugnisse, Beuth Verlag, Berlin, (1993).

DOI: 10.31030/2598101