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

Härtel M, Pfeiffer S, Schmaltz S, Söhngen B, Kulawinski D, Willner K, Henkel S, Biermann H, Wagner MFX (2018)


Publication Language: English

Publication Type: Journal article, Original article

Publication year: 2018

Journal

Book Volume: 54

Journal Issue: 1

DOI: 10.1111/str.12257

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.

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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).

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