Localization effects in Bammann-Chiesa-Johnson metals with damage delocalization

Koffi Enakoutsa, Fazle R. Ahad, Kiran Solanki, Yustianto Tjiptowidjojo, Douglas J. Bammann

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Scopus citations

Abstract

The presence of softening in the Bammann-Chiesa-Johnson (BCJ) material model presents a major physical drawback: the unlimited localization of strain which results in spurious zero dissipated energy at failure. This difficulty resolves when the BCJ model is modified to incorporate a nonlocal evolution equation for the damage, as proposed by Pijaudier-Cabot and Bazant (1987). The objective of this work is to theoretically assess the ability of such a modified BCJ model to prevent unlimited localization of the strain. To that end, we investigate two localization problems in nonlocal BCJ metals: appearance of a spatial discontinuity of the velocity gradient in a finite, inhomogeneous body, and localization into finite bands. We show that in spite of the softening arising from the damage, no spatial discontinuity occurs in the velocity gradient. Also, we find that the dissipation energy is continuously distributed in nonlocal BCJ metals and therefore can not localize into zones of vanishing volume. As a result, the appearance of any vanishing width adiabatic shear band is impossible in a nonlocal BCJ metal. Finally, we study the finite element (FE) solution of shear banding in a rectangular mesh, deformed in plane strain tension and containing an imperfection, thereby illustrating the effects of imperfections on the localization of the strain.

Original languageEnglish (US)
Title of host publicationMechanics of Solids, Structures and Fluids; Vibration, Acoustics and Wave Propagation
PublisherAmerican Society of Mechanical Engineers (ASME)
Pages505-515
Number of pages11
ISBN (Print)9780791854945
DOIs
StatePublished - Jan 1 2011
EventASME 2011 International Mechanical Engineering Congress and Exposition, IMECE 2011 - Denver, CO, United States
Duration: Nov 11 2011Nov 17 2011

Publication series

NameASME 2011 International Mechanical Engineering Congress and Exposition, IMECE 2011
Volume8

Other

OtherASME 2011 International Mechanical Engineering Congress and Exposition, IMECE 2011
CountryUnited States
CityDenver, CO
Period11/11/1111/17/11

ASJC Scopus subject areas

  • Mechanical Engineering

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    Enakoutsa, K., Ahad, F. R., Solanki, K., Tjiptowidjojo, Y., & Bammann, D. J. (2011). Localization effects in Bammann-Chiesa-Johnson metals with damage delocalization. In Mechanics of Solids, Structures and Fluids; Vibration, Acoustics and Wave Propagation (pp. 505-515). (ASME 2011 International Mechanical Engineering Congress and Exposition, IMECE 2011; Vol. 8). American Society of Mechanical Engineers (ASME). https://doi.org/10.1115/imece2011-65935