On the forming and fracture limits of sheet metals

• Autorzy: Korhonen A. S. , Manninen T. , Yoon J. W.

Warianty tytułu

PL

O ograniczeniach odkształcenia i pękania blach cienkich

• Języki publikacji: EN

Abstrakty

EN

It became apparent in the late 1980 that all manufacturing processes in the future would be first simulated before industrial implementation. Sheet metal forming was one of the most important applications where this technology could be applied. One of the issues was to represent the plastic behavior of sheet materials. For accurate numerical simulations information is needed on the initial yielding, subsequent work-hardening and final localization of plastic flow and/or fracture. The forming limits have been studied since the mid-1940s, when Gensamer and Lankford and coworkers carried out their tests with steel and aluminum. In this work we discuss the forming and fracture limits of low carbon steel, stainless steel and aluminum. Experimental results on stretch forming, deep drawing and tensile testing will be presented. Hydraulic bulge testing is employed in the stretch forming experiments. Marciniak-type in-plane tests are carried out to study the limit strains in deep drawing. Laser marked grids are used to measure the surface strains and scanning electron microscopy is employed to measure the thickness strains and to study the fracture surfaces.

PL

Badaniom poddane zostały ograniczenia możliwości odkształcania i pojawianie się pęknięć w blachach ze stali nierdzewnej i aluminium. Test hydraulicznego wybrzuszenia został przeprowadzony w procesie formowania z rozciąganiem. Test typu Marciniaka oraz testy rozciągania zostały przeprowadzone w celu zbadania granicznej odkształcalności. Siatka naniesiona metodą sitodruku i laserem została użyta do pomiaru odkształceń powierzchni próbki. Ponadto, użyto mikroskopu skaningowego do pomiaru odkształceń na grubości i badania powierzchni pęknięć.

Słowa kluczowe

EN

forming limits; fracture; aluminum; stainless steel

• Wydawca: Wydawnictwa AGH
• Czasopismo: Computer Methods in Materials Science
• Rocznik: 2009
• Tom: Vol. 9, No. 1
• Strony: 143--147
• Opis fizyczny: Bibliogr. 11 poz., rys.

Twórcy

autor

Korhonen A. S.

autor

Manninen T.

autor

Yoon J. W.

• Department of Materials Science and Engineering, Helsinki University of Technology,

Bibliografia

• 1.       Arrieux, R., Bedrin, C. and Boivin, M., Determination of an intrinsic forming limit stress diagram for isotropic metal sheets, 12th Biennial Meeting of the    International Deep Drawing Research Group, May 24-28, 1982, S. Margherita Ligure, Italy, Working Group Meetings, WG I, 1982, 61-71.
• 2.       Barlat, F., Material modelling for sheet metal forming simulations, Proceedings of the Numisheet 2008, ed. Hora P., Interlaken, September l - 5, 2008, Part A, 27-36.
• 3.       Gensamer, M., 1946, Strength and ductility, Trans. Am. Soc. Metals, 36, 2008, 30-60.
• 4.       Korhonen, A.S., Localization of Plastic Flow and Ductile Fracture in Metals, Acta Polytechnica Scandinavica. Ch, 144, 1980,33.
• 5.       Korhonen, A.S., Manninen, T., Forming and fracture limits of austenitic stainless steel sheets, Materials Science and Engineering A, 488, 2008, 157-166.
• 6.       Lankford, W.T., Low, J.R. and Gensamer, M., The Plastic Flow of Aluminum Sheet Under Combined Loads, Trans. AIME, 171, 1947,574-604.
• 7.       Makinouchi, A., Teodosiu, C. and Nakagawa, T., Advance in FEM Simulation and its Related Technologies in Sheet Metal Forming, Annals of the CIRP 47, 2, 1998, 641-649.
• 8.       prEN ISO 12004-2, 2008, Metallic materials. Sheet and strip. Determination of forming-limit curves. Part 2: Determination   of forming-limit   curves   in   the   laboratory (ISO/FDIS 12004-2:2008)
• 9.       Słota, J., Spiśak, M., Comparison the forming - limit diagram (FLD) models for drawing quality (DQ) steel sheets, METABK 44, 4, 2005, 249-253.
• 10.      Wu, P.D., Jain, M., Savoie, J., McEwen, S.R., Tugcu, P., Neale, K.W., Evaluation of anisotropic yield functions for aluminium sheets, International Journal of Plasticity, 19, 2003, 121-138.
• 11.      Yoon, J. W., Dick, R.E., Barlat, F., Hong, S.H., On the Use of Stress-Based Forming Limit Curve for Forming and Fracture, Proc. of the ICTP 2008, TB3-1, 2008, 708-722.