Micromechanical analysis on the influence of the Lode parameter on void growth and coalescence
2011 (English)In: International Journal of Solids and Structures, ISSN 0020-7683, E-ISSN 1879-2146, Vol. 48, no 6, 925-938 p.Article in journal (Refereed) Published
A micromechanical model consisting of a band with a square array of equally sized cells, with a spherical void located in each cell, is developed. The band is allowed a certain inclination and the periodic arrangement of the cells allow the study of a single unit cell for which fully periodic boundary conditions are applied. The model is based on the theoretical framework of plastic localization and is in essence the micromechanical model by Barsoum and Faleskog (Barsoum, I., Faleskog, J., 2007. Rupture mechanisms in combined tension and shear-micromechanics. International Journal of Solids and Structures 44(17), 5481-5498) with the extension accounting for the band orientation. The effect of band inclination is significant on the strain to localization and cannot be disregarded. The macroscopic stress state is characterized by the stress triaxiality and the Lode parameter. The model is used to investigate the influence of the stress state on void growth and coalescence. It is found that the Lode parameter exerts a strong influence on the void shape evolution and void growth rate as well as the localized deformation behavior. At high stress triaxiality level the influence of the Lode parameter is not as marked and the overall ductility is set by the stress triaxiality. For a dominating shear stress state localization into a band cannot be regarded as a void coalescence criterion predicting material failure. A coalescence criterion operative at dominating shear stress state is needed.
Place, publisher, year, edition, pages
2011. Vol. 48, no 6, 925-938 p.
Micromechanics, Localization, Ductile failure, Void coalescence, Void growth, Lode parameter
IdentifiersURN: urn:nbn:se:kth:diva-31625DOI: 10.1016/j.ijsolstr.2010.11.028ISI: 000287892800006ScopusID: 2-s2.0-79251593510OAI: oai:DiVA.org:kth-31625DiVA: diva2:405595
FunderSwedish Research Council, 621-2004-5121
QC 201103232011-03-232011-03-212011-03-23Bibliographically approved