Rupture mechanisms in combined tension and shear - Micromechanics
2007 (English)In: International Journal of Solids and Structures, ISSN 0020-7683, E-ISSN 1879-2146, Vol. 44, no 17, 5481-5498 p.Article in journal (Refereed) Published
A micromechanics model based on the theoretical framework of plastic localization into a band introduced by Rice is developed. The model consists of a planar band with a square array of equally sized cells, with a spherical void located in the centre of each cell. The periodic arrangement of the cells allows the study of a single unit cell for which fully periodic boundary conditions are applied. The micromechanics model is applied to analyze failure by ductile rupture in experiments on double notched tube specimens subjected to combined tension and torsion carried out by the present authors. The stress state is characterized in terms of the stress triaxiality and the Lode parameter. Two rupture mechanisms can be identified, void coalescence by internal necking at high triaxiality and void coalescence by internal shearing at low triaxiality. For the internal necking mechanism, failure is assumed to occur when the deformation localizes into a planar band and is closely associated with extensive void growth until impingement of voids. For the internal shearing mechanism, a simple criterion based on the attainment of a critical value of shear deformation is utilized. The two failure criteria capture the transition between the two rupture mechanisms successfully and are in good agreement with the experimental result.
Place, publisher, year, edition, pages
2007. Vol. 44, no 17, 5481-5498 p.
micromechanics; mixed mode ductile fracture; rupture mechanisms; void coalescence
IdentifiersURN: urn:nbn:se:kth:diva-8100DOI: 10.1016/j.ijsolstr.2007.01.010ISI: 000248879300005ScopusID: 2-s2.0-34447284814OAI: oai:DiVA.org:kth-8100DiVA: diva2:13330
QC 201006212000-03-102000-03-102010-07-02Bibliographically approved