Modelling of the plastic behaviour of structural steel based on biaxial testing

• Published in: Journal of constructional steel research Vol. 46; no. 1-3; pp. 404 - 405
• Main Authors: Granlund, J, Olsson, A
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.1998
• Subjects: biaxial testing; constitutive modelling; plasticity; Steel Structures; Structural steel; Stålbyggnad; biaxial testing; plasticity; Structural steel; constitutive modelling
• ISSN: 0143-974X; 1873-5983; 1873-5983
• DOI: 10.1016/S0143-974X(98)80062-X

This paper presents a concept for biaxial testing of structural steel in the principal plane sigma1 -sigma2. Flat cruciform specimens are used which allow for testing in the most common delivery state. Lateral support plates are also developed in order to prevent lateral buckling and thus providing for compression tests as well. Special attention has been devoted to design the cross shaped specimen in order to allow the stress in the gauge area to be determined from external load. A large number of tests have been performed in order to study the initial and subsequent yield criteria. Two different steel grades, one high strength and one mild structural steel, have been tested. The results show that the initial yield criteria falls between the von Mises and Tresca criteria. The subsequent yield criteria are characterized by a pronounced Bauschinger effect for both steel grades. A new constitutive model for structural steel that can describe the Bauschinger effect in a more general way is proposed. The improvement in the prediction of the response in subsequent loading opposite to preloading is significant. The proposed model requires only three additional parameters compared to isotropic hardening.