ArticleName |
Features of calculating power parameters for straightening
bimetallic sheet blanks |
ArticleAuthorData |
Moscow Polytechnic University, Moscow, Russia
S. A. Tipalin, Cand. Eng., Prof., Dept. of Materials Forming and Additive Technologies, e-mail: tsa_mami@mail.ru Yu. G. Kalpin, Dr. Eng., Prof., Dept. of Materials Forming and Additive Technologies N. A. Kupriyanova, Graduate Student, Dept. of Materials Forming and Additive Technologies |
Abstract |
In the process of cutting sheet material, pre-processing and transportation of sheet blanks, their curvature is possible. To recovering their shape, the editing operation by compression is used at a pressure lower than the yield strength of the semi-finished product material. The process of editing a bimetallic billet with small curvature from layers differing in their physical properties is considered, at the next assumptions: we neglect of material hardening, the Bauschinger effect, friction of the semi-finished product on the stamp’s surface due to the smallness of plastic deformations during editing; we suppose, that the stress and deformation’s neutral layers at straightening of the curved billet coincide with each other and there are no initial residual stresses in the layers. As a result of the stress-strain state analysis, the mathematical dependencies were obtained that allow us to calculate the deformations and stresses in various layers of the semifinished product at compression by flat strikers, as well as were obtained the detail’s residual curvature after the operation and the necessary pressure forces, which are necessary to select the appropriate equipment. The analysis of picture changes in the stress distribution pattern in the process of increasing the tool pressure on the billet is performed, and the calculation features for finding the appearing deformation are mathematically presented. The character of changing in the bending moment from the applied compressive pressure between the flat strikers on the bimetallic billet at different initial bending radii is graphically presented. As an example, the process of editing the “tank cap” detail, used in the chemical industry and consisted from bimetal (of the layers of 45 and 65G steels), is considered. In this material, the thickness ratio of the soft and hard layers is 4:1, and the total thickness of bimetallic billet equals 20 mm. During the calculations, it was found that when creating a pressure close to the yield strength of the soft layer, the detail’s buckling decreases from 3.5 mm to 2.4 mm. |
keywords |
Sheet metal straightening, strip straightening, bimetal, sheet blanks, flat strikers,
residual curvature, deformation, radius change, yield strength, stress diagram |
References |
1. Slonim A. Z., Sonin A. L. Straightening of sheet and long metal (technology and equipment). Moscow : Metallurgiya, 1981. 232 p. 2. Kotov K. A., Bolobanova N. L., Nushtaev D. V. Modeling the stress state of a steel strip with a roller leveling machine under cyclic alternating deformations. Steel in Translation. 2020. Vol. 50. No. 11. pp. 750–755. 3. Shinkin V. N. Preliminary straightening of steel strip. Chernye Metally. 2018. No. 5. pp. 34–40. 4. Mathieu N., Potier-Ferry M., Zahrouni H. Reduction of flatness defects in thin metal sheets by a pure tension leveler. International Journal of Mechanical Sciences. 2017. Vol. 122. pp. 267–276. 5. Liu Z., Wang Y., Yan X. A new model for the plate leveling process based on curvature integration method. International Journal of Mechanical Sciences. 2012. Vol. 54. No. 1. pp. 213–224. 6. Kokhan L. S., Morozov Yu. A., Krutina E. V. Choice of criteria to find deformation zone regions during lengthwise rolling. Russian Metallurgy (Metally). 2018. No. 13. pp. 1279–1281. 7. Diegelmann V., Zwickel G., Ulrich M., Gouveia H. et al. Novel method for setting the mechanical and topographic properties of strips within one process step. Chernye Metally. 2014. No. 7. pp. 36–41. 8. Maksimov E. A., Shatalov R. L., Ustinovsky E. P. Development of a methodology for calculating the gap when straightening rolled sheets on a roller straightening machine. Metallurg. 2021. No. 1. pp. 56–61. 9. Maksimov E. A., Shatalov R. L. Mathematical model for calculating the parameters of straightening section profiles on a roller straightening machine. Chernye Metally. 2021. No. 6. pp. 14–18. 10. Remnev K. S. Stability of thin strip made from anisotropic material during extension straightening. Izvestiya Tulskogo gosudarstvennogo universiteta. Technicheskie nauki. 2013. No. 4. pp. 96–107. 11. Noritsyn I. A., Kalpin Yu. G., Boychenko A. I. Determination of specific forces when straightening sheet blanks in dies. Vestnik mashinostroeniya. 1967. No. 3. pp. 63–66. 12. Ryabov V. A. Determination of stresses in layers of a sheet part during pressure straightening. Izvestiya MGTU MAMI. 2013. Vol. 2. No. 2 (16). pp. 175–178. 13. Shinkin V. N. Elastoplastic flexure of round steel beams. 1. Springback coefficient. Steel in Translation. 2018. Vol. 48. No. 3. pp. 149–153. 14. Shinkin V. N. Elastoplastic flexure of round steel beams. 2. Residual stress. Steel in Translation. 2018. Vol. 48. No. 11. pp. 718–723. 15. Bykov A. A. Development of bimetal production. Metallurg. 2009. No. 8. pp. 70–75. 16. Chernov V. V., Andreeva L. P. Heat exchange in heating units when high-emissivity-factor coatings on heat-absorbing surfaces are used. Russian Metallurgy (Metally). 2021. Vol. 6. pp. 685–688. 17. Tipalin S. A., Shpunkin N. F., Kolesov A. V. Elastic bending of a bimetallic sheet. Izvestiya MGTU MAMI. 2013. Vol. 2. No. 1 (15). pp. 103–106. 18. Tipalin S. A., Kuchkovsky Yu. P., Saprykin B. Yu., Tipalina A. V. Study of bimetal deformation using the AutoForm software package. Kuznechno-shtampovochnoe proizvodstvo. Obrabotka materialov davleniem. 2017. No. 8. pp. 34–37. 19. Plokhikh A. I., Safonov M. D., Kolesnikov A. G., Karpukhin S. D. Relaxation mechanism of interlayer stresses in multilayer steel materials. Aviatsionnye materialy i tekhnologii. 2018. No. 2 (51). pp. 26–32. 20. Kalpin Yu. G., Perfilov V. I., Petrov P. A., Ryabov V. A., Filippov Yu. K. Resistance to deformation and plasticity of metals when forming. Moscow : Mashinostroenie, 2011. 244 p. |