The catastrophic development of shear localization in thermoviscoplastic materials
Résumé
Thermomechanical coupling and thermal softening are the critical material properties in the development of adiabatic shear bands. Besides the material effects, the sample geometrical imperfections and the material structural defects are regarded as providing the sites for the onset of the localization process. In this paper, the influence of the shape and size of the imperfections on the localization of the plastic flow in simple shear are analyzed within the framework of a nonlinear model : localization criteria are given in which the sharpness of the defects modulates the rheological effects. It is shown that, more than their size, the sharpness of the local imperfections may help to explain the observed scatter in the nominal failure deformation.
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Origine : Accord explicite pour ce dépôt
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