The limit forming estimation of multi-stage thin-walled vessel cold forming technological process
DOI:
https://doi.org/10.7242/2658-705X/2021.2.5Keywords:
multi-stage technological process, cold sheet stamping, numerical calculation, anisotropic plasticity, limit strains, low-carbon steel, material model identification, experimental confirmationAbstract
The multi-stage technological process of cold stamping of a thin-walled vessel made of sheet steel was evaluated taking into account technological heredity. The quality of the product is evaluated by the distance of its deformed state from the limit states on the strain diagram. To calculate the process, the model of large plastic deformations of the anisotropic shell is used, taking into account the dynamics and contact interactions with the tool, which was numerically implemented in the LS-DYNA® package. Models of plastic flow of an anisotropic sheet, associated with the Barlat criterion Yld 2000-2d, with the power law of isotropic strain hardening, the Peng - Landel potential of nonlinear elastic behavior of a polyurethane die, and the Coulomb friction law of contact interaction of the product with the tool are used from the package library. These models constants for low-carbon sheet steel DC04EK 0,7 mm and polyurethane SKU-PFL were identified from experimental data. The forming limit curve was built on the distortion of the coordinate grid near the zones of strain localization and failure of the vessel in the technological process without intermediate annealing and in the failure test under uniaxial tension. The features of the strain paths in the control points of the vessel at each stage of the technological process, including the sequence of operations of drawing, distributing and reduction, are studied. The path calculation was confirmed by an experiment using pressing equipment as a test. It is established that the operation of distributing the workpiece after its drawing quickly leads to the limit state and therefore requires a preliminary recovering the plasticity resource by annealing. There is a preference for forming the relief of the vessel by smaller degrees of distribution and greater degrees of reduction for elimination of the limit states and the operation of intermediate annealing.
References
- Banabic D. Sheet metal forming processes. Constitutive modelling and numerical simulation. Springer, 2010. - 301 p
- Hu P., Ma N., Liu L., Zhu Y. Theories, methods and numerical technology of sheet metal cold and hot forming. Analysis, simulation and engineering applications. Springer, 2013. - 210 p
- Bruschi S., Altan T., Banabic D. [et al.] Testing and modelling of material behaviour and formability in sheet metal forming // CIRP Annals. - 2014. - Vol. 63. - P. 727-749
- Keller I.E., Petuhov D.S., Kazancev A.V., Trofimov V.N. Diagramma predel’nyh deformacij pri goracej listovoj stampovke metallov. Obzor modelej materiala, kriteriev vazkogo razrusenia i standartnyh ispytanij // Vestn. Samarskogo gos. tehn. un-ta. Ser. Fiz.-mat. nauki. - 2018. - T. 22. - No 3. - S. 447-486
- ariani P.F., Dal Negro T., Bruschi S. Testing and modelling of material response to deformation in bulk metal forming // CIRP Annals. - 2004. - Vol. 53. - P. 573-595
- Kim B.J., Van Tyne C.J., Lee M.Y., Moon Y.H. Finite element analysis and experimental confirmation of warm hydroforming process for aluminum alloy // J. Mater. Process. Tech. - 2007. - Vol. 187-188. - P. 296-299
- Shafaat M.A., Abbasi M., Ketabchi M. Investigation into wall wrinkling in deep drawing process of conical cups // J. Mater. Process. Tech. - 2011. - Vol. 211. - P. 1783-1795
- Andrade F.X.C., Feucht M., Haufe A., Neukamm F. An incremental stress state dependent damage model for ductile failure prediction // Int. J. Fract. - 2016. - Vol. 200. - P. 127-150
- Neto D.M., Oliveira M.C., Dick R.E. [et al.] Numerical and experimental analysis of wrinkling during the cup drawing of an AA5042 aluminium alloy // Int. J. Mater. Form. - 2017. - Vol. 10. - P. 125-138
- Khan A.S., Huang S. Continuum theory of plasticity. John Wiley & Sons, 1995. - 421 p
- Barlat F., Brem J.C., Yoon J.W. [et al.] Plane stress yield function for aluminum alloy sheets - part 1: theory // Int. J. Plast. - 2003. - Vol. 19. - P. 1297-1319
- Adamov A.A., Keller I.E., Petuhov D.S. Eksperimental’naa identifikacia zakonov plasticnosti i razrusenia malouglerodistoj listovoj stali dla modelirovania holodnoj stampovki // PPP. - 2019. - T. 81. - No 2. - S. 202-211
- LS-DYNA(R) Keyword user’s manual. Vol. II. Material models. Version R10.0. LSTC, 2017. - 1682 p
- Keller I.E., Kazancev A.V., Adamov A.A., Petuhov D.S. Modelirovanie mnogoetapnoj holodnoj stampovki tonkostennogo sosuda // PPP. - 2020. - T. 82. - No 1. - S. 75-88
- Maker B.N., Zhu X. Input parameters for springback simulation using LS-DYNA // 6th Int. LS-DYNA Conf. Detroit, USA, April, 2000. - 12 p
- Maker B.N., Zhu X. Input parameters for metal forming simulation using LS-DYNA // 3rd European LS-DYNA Conf. Paris, France, June, 2001. - 10 p
- Hill R. A theory of the yielding and plastic flow of anisotropic metals // Proc. R. Soc. Lond. A. - 1948. - Vol. 193. - P. 281-297
- Yoon J.W., Dick R.E., Barlat F. A new analytical theory for earing generated from anisotropic plasticity // Int. J. Plast. - 2011. - Vol. 27. - P. 1165-1184
- Chung K., Kim D., Park T. Analytical derivation of earing in circular cup drawing based on simple tension properties // Eur. J. Mech. Solid. - 2011. - Vol. 30. - P. 275-280
- Isik K., Silva M.B., Tekkaya A.E., Martins P.A.F. Formability limits by fracture in sheet metal forming // J. Mater. Process. Tech. 2014. - Vol. 214. - P. 1557-1565
- ISO 12004-2:2008. Metallic materials - Sheet and strip - Determination of forming-limit curves - Part 2: Determination of forming limit curves in the laboratory. International Organization for Standardization, 2008. - 27 p
- Graf A., Hosford W.F. Effect of changing strain paths on forming limit diagrams of Al 2008-T4 // MTA. - 1993. - Vol. 24. - P. 2503-2512
- Graf A., Hosford W.F. The influence of strain-path changes on forming limit diagrams of Al 6111 T4 // Int. J. Mech. Sci. - 1994. - Vol. 36. - P. 897-910
- Kazancev A.V., Keller I.E. Ocenka mnogoetapnogo tehnologiceskogo processa holodnoj listovoj stampovki tonkostennogo sosuda s tocki zrenia predel’nyh deformacij // Vycislitel’naa mehanika splosnyh sred. - 2020. - T. 13. - No 2. - S.123-133
- Kazancev A.V., Keller I.E. Rascet mnogoetapnogo processa listovoj stampovki tonkostennogo sosuda i ego ocenka s tocki zrenia predel’nyh deformacij // Vestnik CGPU im. I.A. Akovleva. Ser.: Mehanika predel’nogo sostoania. - 2020. - No 4 (46). - S. 84-92