Stress-state dependent fracture characterisation and modelling of an AZ31 magnesium sheet alloy at elevated temperatures

authored by: Bernd Arno Behrens, Alexander Chugreev, Matthäus Dykiert
Abstract: Due to a high specific strength, magnesium alloys have a high potential to be considered for lightweight solutions in automotive industry. For the numerical design of forming processes, it is important to describe the yielding as well as the fracture behaviour of a material as precisely as possible. In order to fully characterise the fracture behaviour of an AZ31 magnesium sheet alloy at elevated temperatures, a heated test setup for uniaxial tensile machines was developed. The setup allows an adjustment of the load application angle whereby a stress variation is achieved in the centre of the specimen. In order to determine the fracture strain for different temperatures and for varying stress states, a shear stress specimen (also known as butterfly specimen) was considered to perform mechanical experiments by means of this setup. Using numerical simulations, the specific stress development and strain value in the fracture zone, which is needed to calibrate stress state fracture models, was determined for each loading angle and temperature. For this purpose, an orthotropic yield criterion CPB06, which is suitable for depiction of the particular flow behaviour of magnesium alloys (e. g. compression-tension asymmetry), was used. By this means, sufficient data for the calibration of common stress state based fracture models could be provided and the MMC- (Modified Mohr-Coulomb) fracture model was parameterised.
Organisation(s): Institute of Metal Forming and Metal Forming Machines
Type: Conference article
Journal: Procedia Manufacturing
Volume: 29
Pages: 450-457
No. of pages: 8
ISSN: 2351-9789
Publication date: 2019
Publication status: Published
ASJC Scopus subject areas: Industrial and Manufacturing Engineering, Artificial Intelligence
Electronic version(s): https://doi.org/10.1016/j.promfg.2019.02.161 (Access: Open)
https://doi.org/10.15488/10886 (Access: Open)
: Details in the research portal "Research@Leibniz University"

BibTeX

@article{08f1dfb7d9ea4c2db6a6f5fa3c136126,
title = "Stress-state dependent fracture characterisation and modelling of an AZ31 magnesium sheet alloy at elevated temperatures",
abstract = "Due to a high specific strength, magnesium alloys have a high potential to be considered for lightweight solutions in automotive industry. For the numerical design of forming processes, it is important to describe the yielding as well as the fracture behaviour of a material as precisely as possible. In order to fully characterise the fracture behaviour of an AZ31 magnesium sheet alloy at elevated temperatures, a heated test setup for uniaxial tensile machines was developed. The setup allows an adjustment of the load application angle whereby a stress variation is achieved in the centre of the specimen. In order to determine the fracture strain for different temperatures and for varying stress states, a shear stress specimen (also known as butterfly specimen) was considered to perform mechanical experiments by means of this setup. Using numerical simulations, the specific stress development and strain value in the fracture zone, which is needed to calibrate stress state fracture models, was determined for each loading angle and temperature. For this purpose, an orthotropic yield criterion CPB06, which is suitable for depiction of the particular flow behaviour of magnesium alloys (e. g. compression-tension asymmetry), was used. By this means, sufficient data for the calibration of common stress state based fracture models could be provided and the MMC- (Modified Mohr-Coulomb) fracture model was parameterised.",
keywords = "Fracture characterisation, Magnesium sheet alloy AZ31, Modified Mohr-Coulomb, Butterfly specimen",
author = "Behrens, {Bernd Arno} and Alexander Chugreev and Matth{\"a}us Dykiert",
note = "Funding Information: The authors are much obliged to the DFG (Deutsche Forschungsgemeinschaft, German Research Foundation) for the financial support of project 44192561.; 18th International Conference on Sheet Metal, SHEMET 2019 ; Conference date: 15-04-2019 Through 17-04-2019",
year = "2019",
doi = "10.1016/j.promfg.2019.02.161",
language = "English",
volume = "29",
pages = "450--457",
journal = "Procedia Manufacturing",
issn = "2351-9789",
publisher = "Elsevier BV",
}