Plasticity and fracture of martensitic boron steel under plane stress conditions

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES

卷:46

Article

Mohr, Dirk^1,2  Ebnoether, Fabien^2,3 

[1] Ecole Polytech, CNRS, UMR 7649, Solid Mech Lab,Dept Mech,LMS, F-91128 Palaiseau, France

[2] MIT, Dept Mech Engn, Impact & Crashworthiness Lab, Cambridge, MA 02139 USA

[3] Swiss Fed Inst Technol, Dept Mech & Proc Engn, Zurich, Switzerland

关键词: Biaxial experiments;    Ductile fracture;    Finite element model;    Martensitic steel;    Plasticity;    Stress triaxiality;   

DOI  :  10.1016/j.ijsolstr.2009.05.011

来源: Elsevier

【 摘 要 】

Two series of multiaxial experiments are performed to characterize the mechanical behavior of a hot formed martensitic 22MnB5 boron steel. In the first series, flat specimens of uniform cross-section are subjected to various combinations of tensile and shear loading to characterize the elasto-plastic response. Butterfly-shaped specimens of non-uniform cross-section are used for the second series to study the onset of fracture in the martensitic steel. It is found from the analysis of the experimental results that the planar isotropic Hill'48 yield function along with an associated flow rule provides good estimates of the stress-strain response over a wide range of loading paths. The fracture experiments demonstrate that the crack initiation depends strongly on the loading state. A simple stress triaxiality dependent phenomenological fracture model is calibrated to describe the onset of fracture. Using the proposed plasticity and fracture model, numerical simulations of the fracture of tensile specimens of different notch radii are performed and compared with experiments. (C) 2009 Elsevier Ltd. All rights reserved.

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