On the identification of an effective cross section for a cruciform specimen

Journal article
(Original article)


Publication Details

Author(s): Härtel M, Pfeiffer S, Schmaltz S, Söhngen B, Kulawinski D, Willner K, Henkel S, Biermann H, Wagner MFX
Journal: Strain
Publication year: 2018
Volume: 54
Journal issue: 1
ISSN: 1475-1305
Language: English


Abstract


Biaxial tensile testing of sheet metals is becoming increasingly popular for sheet metal


forming. Determining equivalent stresses in biaxial tensile specimens is more


complicated than in conventional uniaxial tensile specimens. In the present study, we


compare four different approaches to calculate effective stresses during biaxial tensile


loading of a cruciform specimen: (i) partial unloading method, where stresses are


determined based on force-strain curves; (ii) identification with uniaxial tensile testing;


(iii) an analysis of equivalent biaxial tests; (iv) numerical simulations. Considering


experimental results for an AA1050 aluminum alloy and for a low-carbon steel DC06,


we show that, for the cruciform sample studied here, two methods do not yield


physically reasonable results: the uniaxial approach does not properly take into


account the effect of transverse loading, and the equivalent biaxial approach exhibits


uncertainties in strain measurement data. The most comprehensible approach is the


numerical method; because it also yields detailed information about the local stress


and strain states. The numerical results are in excellent agreement with the partial


unloading method in terms of the initial flow stress and of effective stress-strain curves


for strains up to 0.02, with both methods predicting a similar effective cross section of


18.0 mm2 for the considered specimen.


FAU Authors / FAU Editors

Schmaltz, Stefan
Sonderforschungsbereich/Transregio 73 Umformtechnische Herstellung von komplexen Funktionsbauteilen mit Nebenformelementen aus Feinblechen - Blechmassivumformung
Söhngen, Benjamin
Sonderforschungsbereich/Transregio 73 Umformtechnische Herstellung von komplexen Funktionsbauteilen mit Nebenformelementen aus Feinblechen - Blechmassivumformung
Willner, Kai Prof. Dr.-Ing.
Professur für Strukturmechanik


How to cite

APA:
Härtel, M., Pfeiffer, S., Schmaltz, S., Söhngen, B., Kulawinski, D., Willner, K.,... Wagner, M.F.-X. (2018). On the identification of an effective cross section for a cruciform specimen. Strain, 54(1). https://dx.doi.org/10.1111/str.12257

MLA:
Härtel, Markus, et al. "On the identification of an effective cross section for a cruciform specimen." Strain 54.1 (2018).

BibTeX: 

Last updated on 2019-01-01 at 19:10