Publication detail
Lode dependent plasticity coupled with nonlinear damage accumulation for ductile fracture of aluminium alloy
ŠEBEK, F. PETRUŠKA, J. KUBÍK, P.
Czech title
Plasticita závislá na Lodeho svázaná s nelineární kumulací poškození pro tvárné porušování slitiny hliníku
English title
Lode dependent plasticity coupled with nonlinear damage accumulation for ductile fracture of aluminium alloy
Type
journal article in Web of Science
Language
en
Original abstract
The experimental program was designed and proportional tests carried out at a room temperature on aluminium alloy 2024-T351. These concerned tension, torsion and compression, in order to investigate the damage accumulation nonlinearity and to reliably calibrate new phenomenological ductile fracture criterion. This fracture model, KHPS2, expressed through the fracture strain, was dependent on the stress triaxiality and normalized third invariant of deviatoric stress tensor. The ductile fracture model was then coupled with the yield criterion, as in the continuum damage mechanics, using the material softening. The plasticity model was considered in the form of taking into account the Lode dependence for investigated material, through normalized third invariant of deviatoric stress tensor. The whole approach, fully applicable to multiaxial ductile fracture related problems, was implemented using the user subroutine into the commercial software, based on the explicit finite element method. In the end, the proposed approach was verified using chosen realized fracture tests, which were used in the calibration, and newly designed KHPS2 criterion along with an existing one—modified Hosford–Coulomb model. The latter model showed better performance in simulations despite worse approximation ability, which can be attributed to its micromechanically-motivated formulation.
Czech abstract
Experimentální program byl navrhnut a byly provedeny proporcionální testy za pokojové teploty na slitině hliníku 2024-T351. Tyto zahrnovaly tah, krut a tlak pro studium nelinearity kumulace poškození a pro spolehlivou kalibraci nového fenomenologického kritéria tvárného porušování. Tento model porušování, KHPS2, vyjádřený skrz lomové přetvoření, byl závislý na triaxialitě napětí a normalizovaném třetím invariantu deviátoru tenzoru napětí. Model tvárného porušování byl poté svázán s podmínkou plasticity pomocí změkčení materiálu, tak jako v mechanice poškození kontinua. Model plasticity byl uvažován ve formě beroucí v úvahu Lodeho závislost pro studovaný materiál, pomocí normalizovaného třetího invariantu deviátoru tenzoru napětí. Celý postup, plně aplikovatelný na problémy víceosého tvárného porušování, byl implementován pomocí uživatelského podprogramu do komerčního programu, založeného na explicitní metodě konečných prvků. Navržený postup byl nakonec verifikován pomocí vybraných provedených lomových testů, které byly použity v kalibraci a nově navrženého kritéria KHPS2 spolu s jedním existujícím—modifikovaným Hosfordovým–Coulombovým modelem. Poslední model vykazoval lepší výkonnost v simulacích navzdory horší aproximační schopnosti, což může být přisouzeno jeho mikromechanicky motivované formulaci.
English abstract
The experimental program was designed and proportional tests carried out at a room temperature on aluminium alloy 2024-T351. These concerned tension, torsion and compression, in order to investigate the damage accumulation nonlinearity and to reliably calibrate new phenomenological ductile fracture criterion. This fracture model, KHPS2, expressed through the fracture strain, was dependent on the stress triaxiality and normalized third invariant of deviatoric stress tensor. The ductile fracture model was then coupled with the yield criterion, as in the continuum damage mechanics, using the material softening. The plasticity model was considered in the form of taking into account the Lode dependence for investigated material, through normalized third invariant of deviatoric stress tensor. The whole approach, fully applicable to multiaxial ductile fracture related problems, was implemented using the user subroutine into the commercial software, based on the explicit finite element method. In the end, the proposed approach was verified using chosen realized fracture tests, which were used in the calibration, and newly designed KHPS2 criterion along with an existing one—modified Hosford–Coulomb model. The latter model showed better performance in simulations despite worse approximation ability, which can be attributed to its micromechanically-motivated formulation.
Keywords in Czech
Slitina Al–Mg–Cu; Poškození; Konečný prvek; Elasto–plastický materiál; Změkčení; Polykrystalický materiál
Keywords in English
Al–Mg–Cu alloy; Failure; Finite element; Elastic–plastic material; Weakening; Polycrystalline material
Released
05.01.2018
ISSN
0264-1275
Volume
137
Number
1
Pages from–to
90–107
Pages count
18
BIBTEX
@article{BUT140414,
author="František {Šebek} and Jindřich {Petruška} and Petr {Kubík},
title="Lode dependent plasticity coupled with nonlinear damage accumulation for ductile fracture of aluminium alloy",
year="2018",
volume="137",
number="1",
month="January",
pages="90--107",
issn="0264-1275"
}