Manufacturing Technology 2020, 20(1):92-97 | DOI: 10.21062/mft.2020.005

Influence of Stress State on the Yield Strength of Aluminium Alloy

Jiri Sobotka, Pavel Solfronk, David Korecek

Department of Engineering Technology, Technical University of Liberec. Studentská 1402/2, 461 17 Liberec. Czech Republic.

The basic mechanical properties of structural materials (e.g. yield strength, ultimate tensile strength, uniform and total ductility, anisotropy coefficient, etc.) represent fundamental material characteristics. These parameters are mostly detected by a static tensile test. From the stress state point of view, it is therefore a uniaxial tension stress state. However, the service load usually means acting of wide range of stress states. For this reason, the department of engineering technology at TUL developed a device enabling loading the sample by planar bi-axial loading with the possibility to change ratio of their loading. It is therefore possible to load the material from uniaxial tension to equi-biaxial stretching. The aim of this paper is to determine the change of one basic material mechanical properties (yield strength) based on the adjustment of various stress states - from the conventional uniaxial tensile stress state (static tensile test) to equi-biaxial stretching. The own evaluation is performed on the measured stress-strain curves for the tested aluminium alloy AA6111. The results can then be used not only to describe the effect of stress state on the deformation behaviour of tested material, but can also serve as input data in numerical simulations of forming technologies.

Keywords: Stress state, Yield Strength, Aluminium Alloy, Contact-less Optical Measurement, Bi-axial Testing

Grants and funding:

Technical University of Liberec as part of the project "SGS 21286“ with the support of the Specific University Research Grant, as provided by the Ministry of Education, Youth and Sports of the Czech Republic.

Prepublished online: July 31, 2020; Published: August 6, 2020  Show citation