TR73

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A4 - Incremental Forming (funding period 2)



Fundamental Research and Process Development for the Manufacturing of Load-Optimized Parts by Incremental Sheet-Bulk Metal Forming

Project Status: finished

Last Update: 23.01.2017



Members


The aim of this project is the flexible production of near-net-shape and load optimized functional components from thin sheets using the incremental procedure of sheet-bulk metal forming. The focus is the realization of a defined sheet thickness increase as well as the local setting of the mechanical component properties (e.g. hardness). Unlike the classic description of sheet metal forming processes by using a plane stress and strain state with a material flow predominantly lying in the plane, the application of bulk forming operations onto sheets affects a three-dimensional material flow. The challenge lies in the description and the targeted control of this novel material flow, whereby a mutual influence of the formed functional elements must be must be taken into account. Furthermore, the high local contact pressure leads to a decreased tool life as well as to a tool deformation. Therefore it is necessary to reduce the high tool load to achieve a high dimensional accuracy.

The investigations contain the incremental and locally limited application of bulk forming operations to sheet materials. Based on a developed kinematic-motion-matrix a five-axis special forming press was developed and realized. This prototype machine allows to perform a wide variety of different forming operations with a very flexible temporal and spatial arrangement (Figure 1). The particularly rigid machine structure and the developed special drive concept allow precise tool movements in hundredths of a millimeter, even under load.

Fig. 1: Multiaxispress TR73 with its five axes of motion (1. Ram, 2. Machine table, 3. Turntable, 4a + 4b Additional axes)

 

In the second project period this technology has been made utilizable through the description and the directed control of the material flow. The identified mechanisms provide an efficient instrument for a defined geometric shaping of functional components. Divided into continuous and discrete forming processes and further split due to the processed workpiece region (sheet plane or sheet edge) the processes were analyzed experimentally and numerically. To describe the physical interactions three analytical models were developed and verified in experiments and simulations:

  1. Process forces and resulting material pile-up geometry in an in-plane swaging process (approach: slip-line field method).
  2. Force level and force composition in sheet-bulk indentation on the sheet edge (approach: upper bound method).
  3. Force reduction by superposition of stresses at the incremental gear forming process (approach: slip-line field method).

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Fig. 2: Force reduction by superposition of stresses (experimental set-up and achieved force reduction)

 

With the principle of stress superposition the occurring forming forces at gear forming operations could be reduced by up to 30% (Fig. 2). To improve the form filling of the first gear element three approaches were investigated:

  • Geometrical adaption of the initial sheet shape (Fig. 3, right)
  • Modification of the active tool surfaces with bionic micro-structures (cooperation with subprojects B2 and B5) and
  • Adapted process strategy containing a pre-forming step.

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Fig. 3: Numerical analysis of the incipient and the repeatable indentations (left), improved form filling of the first gear by a geometry adaption of the initial sheet blank (right).


Working Groups


Publications

    2016

    • Gröbel, D.; Schulte, R.; Hildenbrand, P.; Lechner, M.; Engel, U.; Sieczkarek, P.; Wernicke, S.; Tekkaya, A.; Behrens, B.; Hübner, S.; Vucetic, M.; Koch, S.; Merklein, M.: Manufacturing of functional elements by sheet-bulk metal forming processes. In: Production Engineering, 10(2016)1, pp. 63-80
    • Sieczkarek, P.; Wernicke, S.; Weddeling, C.; Martins, P. A. F.; Tekkaya, A.: Local Forming of Gears by Indentation of Sheets. In: Journal of Engineering Manufacture, (2016), DOI: 10.1177/0954405416654190, accepted
    • Wernicke, S.; Sieczkarek, P.; Martins, P. A. F.; Tekkaya, A.: Local Sheet Thickening by In-Plane Swaging. In: International Journal of Mechanical Sciences, (2016), DOI: 10.1016/j.ijmecsci.2016.10.003, accepted
    • Sieczkarek, P.; Silva, C. M. A.; Wernicke, S.; Tekkaya, A.; Martins, P. A. F.: Mechanical Characterization of Materials for Sheet-Bulk Metal Forming. In: RTME Conference, July 11-13, (2016), Aveiro, Portugal, in print
    • 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
    • Sieczkarek, P.; Wernicke, S.; Gies, S.; Martins, P. A. F.; Tekkaya, A.: Incipient and repeatable plastic flow in incremental sheet-bulk forming of gears. In: International Journal of Advanced Manufacturing Technology, (2016)86, DOI 10.1007/s00170-016-8442-6, pp. 3091-3100
    • Isik, K.; Wernicke, S.; Silva, M.B.; Martins, P.A.F.; Tekkaya, A.: Failure by fracture in sheet–bulk metal forming. In: Journal of Strain Analysis; DOI: 10.1177/0309324716639773, 51(2016)5, pp. 387-394

    2015

    • 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
    • Matthias, S.; Kästner, M.; Reithmeier, E.; Sieczkarek, P.; Tekkaya, A.: Forming tool inspection using fiber-optic sensor heads. In: João Tavares, Natal Jorge (Edt.): Computational Vision and Medical Image Processing V, (2015), London, UK: Taylor & Francis Group, pp. 335-339

    2014

    • Sieczkarek, P.; Isik, K.; Ben Khalifa, N.; Martins, P. A. F.; Tekkaya, A.: Mechanics of Sheet-Bulk Indentation. In: Journal of Materials Processing Technology (JMPT), 214(2014), Elsevier, pp. 2387-2394

    2013

    • Sieczkarek, P.; Kwiatkowski, L.; Ben Khalifa, N.; Tekkaya, A.: Novel five-axis forming press for the incremental sheet-bulk metal forming. In: Key Engineering Materials, 554(2013), pp. 1478-1483
    • Salfeld, V.; Krimm, R.; Behrens, B.; Sieczkarek, P.; Ben Khalifa, N.; Tekkaya, A.; Tremmel, S.; Wartzack, S.: Maschinen- und werkzeugseitige Herausforderungen bei der Blechmassivumformung von komplexen Bauteilen. In: Merklein, M., Behrens, B.-A., Tekkaya, A. E. (Edt.): Tagungsband zum 2. Workshop Blechmassivumformung 2013 - DFG Transregio 73, (2013), Bamberg: Meisenbach , pp. 13-36
    • Sieczkarek, P.; Kwiatkowski, L.; Tekkaya, A.; Krebs, E.; Kersting, P.; Tillmann, W.; Herper, J.: Innovative tools to improve incremental bulk forming processes. In: Key Engineering Materials , 554(2013), pp. 1490-1497
    • Kästner, M.; Hausotte, T.; Reithmeier, E.; Loderer, A.; Ohrt, C.; Sieczkarek, P.: Fertigungsnahe Qualitätskontrolle von Werkzeug und Werkstück. In: M. Merklein, B.-A. Behrens, A. E. Tekkaya (Edt.): Tagungsband zum 2. Erlanger Workshop Blechmassivumformung 2013, (2013), Bamberg: Meisenbach, pp. 101-118

    Presentations

      2016

      • 13.07.2016: Mechanical Characterization of Materials for Sheet-Bulk Metal Forming Processes, RTME 2016 Conference, Aveiro, Portugal

      2015

      • 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

      2014

      • 26.02.2014: Sieczkarek, P.; Weddeling, C.; Ben Khalifa, N.; Tekkaya, A.: Herstellung von belastungsangepassten Funktionsbauteilen mittels inkrementeller Blechmassivumformung, 21. Umformtechnisches Kolloquium Hannover, (Poster-Präsentation)

      2013

      • 23.04.2013: Sieczkarek, P.; Kwiatkowski, L.; Ben Khalifa, N.; Tekkaya, A.: Novel five-axis forming press for the incremental sheet-bulk metal forming, ESAFORM Conference 2013, Aveiro, Portugal
      • 23.04.2013: Sieczkarek, P.; Kwiatkowski, L.; Tekkaya, A.; Krebs, E.; Kersting, P.; Tillmann, W.; Herper, J.: Innovative tools to improve incremental bulk forming processes, ESAFORM Conference 2013, Aveiro, Portugal