Zasnova preizkuševališča za upogibno preizkušanje pločevine pri velikih plastičnih deformacijah

Šparovec, Jakob (author), Halilovič, Miroslav (mentor)

Tehnološki procesi preoblikovanja pločevine so dandanes optimirani do skrajnih meja preoblikovalnosti. Modeliranje takšnih procesov je močno zaznamovano z mehanskim odzivom pločevine, ki je v veliki meri pogojen z nelinearnim materialnim obnašanjem pri velikih plastičnih deformacijah. V magistrskem delu smo za namen karakterizacije utrjevanja jeklene pločevine pri velikih plastičnih deformacijah zasnovali upogibni preizkus. Izvedli smo preliminarne numerične simulacije, ki so pokazale, da je z zasnovanim upogibnim preizkusom možno doseči večje plastične deformacije od deformacij, ki bi jih dobili z enoosnim nateznim preizkusom. Izdelali smo postrojenje za izvedbo upogibnega preizkusa, ki je bilo nameščeno v trgalni stroj. Na podlagi opravljenih preizkusov smo pokazali, da pri upogibu pločevine pride do zakasnitve pojava lokalne zožitve in da je z uporabljenim upogibnim preizkusom, s predhodnim enoosnim nateznim obremenjevanjem, možno doseči večje plastične deformacije od tistih, ki jih dosežemo s standardnim enoosnim nateznim preizkusom.

• Language: Slovenian
• Keywords: upogibni preizkus, preoblikovanje pločevine, snovni parametri, krivulja utrjevanja, velike plastične deformacije, lokalna preoblikovalnost, lokalna zožitev, korelacija digitalnih slik
• Work type: Master's thesis/paper (mb22)
• Tipology: 2.09 - Master's Thesis
• Organization: FS - Faculty of Mechanical Engineering
• Year: 2020
• Publisher: [J. Šparovec]
• Number of pages: XXVIII, 79 str.
• UDC: 620.174:621.98:539.3(043.2)
• COBISS.SI-ID: 21473027
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Secondary language

• Language: English
• Title: Bending test design for sheet metal testing at large plastic strains

Abstract

Nowadays, the technological processes of sheet metal forming are optimized to the extreme limits of material formability. The modeling of such processes is strongly characterised by mechanical response of the sheet metal, which is strongly dependent on nonlinear material behavior at large plastic strains. In this master's thesis, we designed a bending test for characterization of hardening behaviour of steel sheet metal at large plastic strains. Preliminary numerical simulations were performed, which showed that with the designed bending test it is possible to achieve higher plastic strains than the strains obtained with a uniaxial tensile test. We made a device for performing a bending test, which was installed in a universal testing machine. Based on the performed experiments, we showed that sheet metal bending hinders the onset of necking and that with the used bending test of prestrained specimens, it is possible to achieve higher plastic strains than those, achieved by using standard uniaxial tensile test.

• Keywords: bending test, sheet metal forming, material parameters, hardening curve, large plastic strains, local formability, necking, digital image correlation