C1 - Friction Law (funding period 2)
Constitutive friction law for the description and optimization of tailored surfaces
Project Status: finished
Last Update: 23.01.2017
Members
Due to locally varying load conditions regarding stress and strain states the tribological conditions are of major importance for sheet-bulk metal forming operations (SBMF). Within the subproject C1 of the collaborative research center TR73, which is a collaboration between the Institute of Applied Mechanics and the Institute of Manufacturing Technology, the main focus is on the investigation of the tribological conditions in SBMF, qualification of tailored surfaces and the further development of a constitutive friction law.
A focal point of the subproject C1 is the investigation and further development of tribological systems. In addition to different lubricants, tailored surfaces are qualified with regard to the applicability to forming processes in SBMF. The investigation of the tribological conditions is done by the use of different laboratory friction test which have been adapted to the process conditions in SBMF. Current results revealed that workpiece-side tailored surfaces in terms of surface adjustments by micro structuring and abrasive blasting are suitable methods for influencing the friction factor m and thus, to control the material flow in SBMF processes. These results have been already proven for different forming processes in SBMF.

Friction factors m of micro structured and abrasive blasted tailored surfaces
In the first funding period a constitutive friction law was developed with the help of a half-space model which was validated experimentally. The friction law determines the resulting friction stress as a function of the locally occurring normal stress. In contrast to finite-element-method which requires a discretization of the volume, the half-space model only needs a surface discretization. As a result, the half-space comes with a reduced computation time and a very fine surface resolution, which in turn helps to yield an accurate numerical analysis of the elastic-plastic contact between the surfaces of worktool and workpiece. In the current funding period, the half-space model is continuously advanced. Effects, such as plastic deformation due to tangential contact or the influence of coated tool surfaces are considered. The constitutive friction law is steadily extended with the resulting outcomes, so that a valid friction law for the complex conditions in sheet-bulk metal forming is provided. Hence, the friction law is implemented in a finite-element-system to be available for general use in forming simulations.

Comparison of resulting mean roughness Ra in dependency on acting normal load p
In the first funding period a constitutive friction law was developed with the help of a half-space model which was validated experimentally. The friction law determines the resulting friction stress as a function of the locally occurring normal stress. In contrast to finite-element-method which requires a discretization of the volume, the half-space model only needs a surface discretization. As a result, the half-space comes with a reduced computation time and a very fine surface resolution, which in turn helps to yield an accurate numerical analysis of the elastic-plastic contact between the surfaces of worktool and workpiece. In the current funding period, the half-space model is continuously advanced. Effects, such as plastic deformation due to tangential contact or the influence coated tool surfaces are considered . The constitutive friction law is being expanded with the resulting outcomes, so that a valid friction law for the complex conditions in sheet-bulk metal forming is provided. Hence, the friction law is implemented in a finite element system to be available for general use in forming simulations.
Working Groups
Publications
2019
- Beyer, F.: Numerische Untersuchungen zur Kontaktmechanik in der Blechmassivumformung, Dissertation(2019), published
2016
- Löffler, M.; Andreas, K.; Engel, U.; Weikert, T.; Tremmel, S.; Wartzack, S.; Stangier, D.; Tillmann, W.; Merklein, M.: Surface modifications for adaption of tribological conditions in sheet-bulk metal forming processes. In: Bobzin, K.; Bouzakis, K.-D.; Denkena, B.; Maier, H.J.; Merklein, M. (Edt.): Proceedings THE "A" Coatings, (2016), PZH Verlag, pp. 13-20
- Löffler, M.; Andreas, K.: Einfluss des Schmierstoffs auf die Werkstückqualität in der Blechmassivumformung. In: Buchmayr, B. (Edt.): Tagungsband XXXV. Verformungskundliches Kolloquium, (2016), accepted
- Beese, S.; Beyer, F.; Blum, H.; Isik, K.; Kumor, D.; Rademacher, A.; Tekkaya, A.; Willner, K.; Wriggers, P.; Zeller, S.; Löhnert, S.: Simulation of Sheet-Bulk Metal Forming Processes with Simufact.forming using User-Subroutines. In: ESAFORM (Edt.): (2016), Nantes, Frankreich, accepted
- Beyer, F.; Willner, K.: A constitutive friction law for sheet-bulk metal forming. In: Tribology Online (Edt.): 11(2016)5, pp. 614-622
- Kersting, P.; Gröbel, D.; Merklein, M.; Sieczkarek, P.; Wernicke, S.; Tekkaya, A.; Krebs, E.; Freiburg, D.; Biermann, D.; Weikert, T.; Tremmel, S.; Stangier, D.; Tillmann, W.; Matthias, S.; Reithmeier, E.; Löffler, M.; Beyer, F.; Willner, K.: Experimental and numcerial analysis of tribological effective surfaces for forming tools in Sheet-Bulk Metal Forming. In: Production Engineering, 10(2016)1, Springer, pp. 37-50
- Merklein, M.; Lechner, M.; Gröbel, D.; Löffler, M.; Schneider, T.; Schulte, R.; Hildenbrand, P.: Innovative approaches for controlling the material flow in sheet-bulk metal forming processes. In: Manufacturing Review, 3(2016)2, pp. 1-17
- Löffler, M.; Andreas, K.; Engel, U.; Merklein, M.: Applicability of blasted blanks for adaption of tribological conditions in sheet-bulk metal forming. In: Procedia CIRP, 45(2016), pp. 239-242
- Küstner, C.; Beyer, F.; Kumor, D.; Loderer, A.; Wartzack, S.; Willner, K.; Blum, H.; Rademacher, A.; Hausotte, T.: Simulation-based development of Pareto-optimized tailored blanks for the use within sheet-bulk metal forming. In: Marjanovic, D.; Storga, M.; Pavkovic, N.; Bojcetic, N.; Skec, S. (Edt.): DS 84: Proceedings of the DESIGN 2016 14th International Design Conference, (2016), Design Society, pp. 291-300
- Beyer, F.; Löffler, M.; Willner, K.; Engel, U.; Merklein, M.: Enhancement of a Constitutive Friction Law by Considering Plastic Smoothing of Rough Surfaces in Dependency on the Bulk Stresses. In: Tribology in Industry, 38(2016)2, pp. 163-175
- Löffler, M.; Engel, U.; Schulte, R.; Gröbel, D.; Krebs, E.; Freiburg, D.; Biermann, D.; Stangier, D.; Tillmann, W.; Weikert, T.; Wartzack, S.; Tremmel, S.; Lucas, H.; Denkena, B.; Merklein, M.: Tribological measures for controlling material flow in sheet-bulk metal forming. In: Production Engineering, 10(2016), pp. 459-470
2015
- Merklein, M.; Löffler, M.; Schneider, T.: Plastic flow and its control in sheet-bulk metal forming of thin-walled functional components. In: CIRP Annals - Manufacturing Technology, 64(2015)1, pp. 248-248
- Löffler, M.; Gröbel, D.; Andreas, K.; Engel, U.; Merklein, M.: Analysis of Effectivness of Locally Adapted Tribological Conditions for Improving Product Quality in Sheet-Bulk Metal Forming. In: Applied Mechnics and Materials, 794(2015), pp. 81-88
- Hense, R.; Kersting, P.; Vierzigmann, U.; Löffler, M.; Biermann, D.; Merklein, M.; Wels, C.: High-Feed Milling of Tailored Surfaces for Sheet-Bulk Metal Forming Tools. In: Production Engineering, 9(2015)2, pp. 215-223
- Beyer, F.; Blum, H.; Kumor, D.; Rademacher, A.; Willner, K.; Schneider, T.: Experimental and simulative investigations of tribology in sheet-bulk metal forming. In: Key Engineering Materials, 639(2015), pp. 283-290
- Löffler, M.; Schneider, T.; Vierzigmann, U.; Engel, U.; Merklein, M.: Locally Adapted Tribological Conditions as a Method for Influencing the Material Flow in Sheet-Bulk Metal Forming Processes. In: Key Engineering Materials, 639(2015), pp. 267-274
- Löffler, M.; Freiburg, D.; Gröbel, D.; Loderer, A.; Matthias, S.; Stangier, D.; Weikert, T.: Untersuchung von Tailored Surfaces hinsichtlich ihres tribologischen Einflusses auf Prozesse der Blechmassivumformung. In: Tekkaya, A. E.; Liewald, M.; Merklein, M.; Behrens, B.-A (Edt.): Tagungsband zum 18. Workshop Simulation in der Umformtechnik & 3. Industriekolloquium Blechmassivumformung 2015 - DFG Transregio 73, (2015), Aachen: Shaker Verlag, pp. 131-146
- Hildenbrand, P.; Sieczkarek, P.; Matthias, S.; Löffler, M.; Besserer, H.; Merklein, M.; Tekkaya, A.; Reithmeier, E.; Maier, H.: Inkrementelles Umformen dünnwandiger Funktionsbauteile unter Einsatz prozessangepasster Halbzeuge durch Verfahren der Blechmassivumformung. In: Tekkaya, A. E.; Liewald, M.; Merklein, M.; Behrens, B.-A. (Edt.): Tagungsband zum 18. Workshop Simulation in der Umformtechnik & 3. Industriekolloquium Blechmassivumformung 2015 - DFG Transregio 73, (2015), Aachen: Shaker Verlag, pp. 149-170
- Beyer, F.; Willner, K.: Determination of a Constitutive Friction Law Using an Elastic-Plastic Half-Space Model. In: G. Zavarise, P. Cinnella and M. Campiti (Edt.): Proc. Appl. Math. Mech., 15(2015)1, Wiley, pp. 173-174
- Beyer, F.; Hauer, F.; Willner, K.: Development of a Constitutive Friction Law based on the Frictional Interaction of Rough Surfaces37(2015)4, pp. 400-412
- Merklein, M.; Gröbel, D.; Löffler, M.; Schneider, T.; Hildenbrand, P.: Sheet-bulk metal forming – forming of functional components from sheet metals. In: Y. Qin, T.A. Dean, J. Lin, S.J. Yuan, F. Vollertsen (Edt.): Proceedings of the 4th International Conference on New Forming Technology, (2015), MATEC Web of Conferences, pp. 01001 1-12
2014
- Schneider, T.; Vierzigmann, U.; Merklein, M.: Analysis of Varying Properties of Semi-finished Products in Sheet-bulk Metal Forming of Functional Components. In: J. W. Yoon, T. B. Stoughton, B. Rolfe, J. H. Beynon, P. Hodgson (Edt.): NUMISHEET 2014: The 9th International Conference and Workshop on Numerical Simulation of 3D Sheet Metal Forming Processes, (2014), pp. 930-933
- Beyer, F.; Willner, K.: Surface Deformation due to Shear and Ploughing in a Halfspace. In: P. Steinmann & G. Leugering (Edt.): Special Issue: 85th Annual Meeting of the International Association of Applied Mathematics and Mechanics (GAMM), 14(2014)1, Weinheim: WILEY-VCH, pp. 239–240
- Gröbel, D.; Koch, J.; Vierzigmann, U.; Engel, U.; Merklein, M.: Investigations and approaches on material flow of non-uniform arranged cavities in sheet bulk metal forming processes. In: Procedia Engineering, 81(2014), pp. 401-406
- Hauer, F.: Die elasto-plastische Einglättung rauer Oberflächen und ihr Einfluss auf die Reibung in der Umformtechnik. In: Schriftenreihe Technische Mechanik, 12(2014), published
2013
- Hauer, F.; Willner, K.: Development of a friction law respecting plastic surface smoothing. In: Key Engineering Materials (Edt.): 554(2013), Durnten - Zurich: Trans Tech Publications Ltd, pp. 1471-1477
- Vierzigmann, U.; Schneider, T.; Koch, J.; Merklein, M.; Engel, U.; Hense, R.; Biermann, D.; Krebs, E.; Kersting, P.; Lucas, H.; Denkena, B.; Herper, J.; Tillmann, W.; Stangier, D.: Untersuchungen von Tailored Surfaces für die Blechmassivumformung mittels angepasstem Ringstauchversuch. In: Merklein, M.; Behrens, B. A., Tekkaya, A. E. (Edt.): 2. Workshop Blechmassivumformung, (2013), Bamberg: Meisenbach, pp. 137-162
- Schmaltz, S.; Landkammer, P.; Beyer, F.; Kumor, D.; Rademacher, A.; Blum, H.; Steinmann, P.; Willner, K.: Vorstellung eines Simulationsbenchmarks für die Blechmassivumformung. In: Merklein, M.; Behrens, B. A., Tekkaya, A. E. (Edt.): 2. Workshop Blechmassivumformung, (2013), Bamberg: Meisenbach, pp. 53-68
- Breitsprecher, T.; Hense, R.; Beyer, F.; Biermann, D.; Wartzack, S.; Willner, K.: Sensitivitätsanalyse der tribologischen Eigenschaften gefräster Oberflächenstrukturen bei der Blechmassivumformung. In: Merklein, M.; Behrens, B. A., Tekkaya, A. E. (Edt.): 2. Workshop Blechmassivumformung, (2013), Bamberg: Meisenbach, pp. 121-136
Presentations
2016
- 07.03.2016: Löffler, M.: Einfluss des Schmierstoffs auf die Werkstückqualität in der Blechmassivumformung, Zauchensee
- 14.03.2016: Löffler, M.: Ansätze zur Steuerung des Stoffflusses mittels maßgeschneiderter tribologischer Systeme, GCFG Sitzung Darmstadt
- 01.04.2016: Löffler, M.: Surface modifications for adaption of tribological conditions in sheet-bulk metal forming processes, THEA Coatings, Hannover
- 27.04.2016: Kumor, D.: Simulation of Sheet-Bulk Metal Forming Processes with Simufact.forming using User-Subroutines, 19th ESAFORM Conference, Nantes, Frankreich
2015
- 26.02.2015: Löffler, M.: Untersuchung von Tailored Surfaces hinsichtlich ihres tribologischen Einflusses auf Prozesse der Blechmassivumformung, Dortmund
- 27.02.2015: Hildenbrand, P.: Inkrementelles Umformen dünnwandiger Funktionsbauteile unter Einsatz prozessangepasster Halbzeuge durch Verfahren der Blechmassivumformung, 18. Workshop Simulation in der Umformtechnik & 3. Industriekolloquium Blechmassivumformung, Dortmund
- 17.03.2015: Löffler, M.: Locally Adapted Tribological Conditions as a Method for Influencing the Material Flow in Sheet-Bulk Metal Forming Processes, Erlangen
- 17.03.2015: Beyer, F.: Experimental and simulative investigations of tribology in sheet-bulk metal forming, Erlangen
- 26.03.2015: Beyer, F.: Determination of a Constitutive Friction Law Using An Elastic-Plastic Half-Space Model, Lecce, Italien
- 16.04.2015: Löffler, M.: Untersuchung von Tailored Surfaces hinsichtlich ihres tribologischen Einflusses auf Prozesse der Blechmassivumformung, Arbeitsgruppensitzung GCFG, Stuttgart
- 06.08.2015: Merklein, M.: Sheet-bulk metal forming – forming of functional components from sheet metals, Glasgow
- 07.09.2015: Löffler, M.: Analysis of effectiveness of locally adapted tribological conditions improving product quality in sheet-bulk metal forming, Hamburg
- 19.09.2015: Beyer, F.: A Constitutive Friction Law for Sheet-Bulk Metal Forming, Tokyo, Japan
- 28.10.2015: Löffler, M.: Lokal angepasste tribologische Bedingungen als eine Möglichkeit zur Beeinflussung des Materialflusses in der Blechmassivumformung, Arbeitsgruppensitzung GCFG, Freiberg
2014
- 28.02.2014: Merklein, M.: Blechmassivumformung: Umformtechnik mit Zukunft, Potsdam
- 13.03.2014: Beyer, F.: Surface Deformation due to Shear and Ploughing in a Halfspace, Erlangen
- 20.05.2014: Merklein, M.: Potenziale und Grenzen der Simulation in der Fertigungstechnik, Marburg
- 02.10.2014: Merklein, M.; Löffler, M.; Vierzigmann, U.: Tribology in Sheet-bulk Metal Forming Processes - Interaction of Tailored Surfaces, Coatings and Material Flow, Thessaloniki, Griechenland
- 26.11.2014: Merklein, M.: Blechmassivumformung - Stand heute, Hagen
2013
- 13.11.2013: Koch, J.: Untersuchung von Tailored Surfaces für die Blechmassivumformung mittels angepasstem Ringstauchversuch, Erlangen
- 13.11.2013: Breitsprecher, T.: Vortrag bearbeiten: Sensitivitätsanalyse der tribologischen Eigenschaften gefräster Oberflächenstrukturen bei der Blechmassivumformung, Erlangen