Behaviour of voids in a shear field

• Published in: International journal of fracture Vol. 158; no. 1; pp. 41 - 49
• Main Author: Tvergaard, Viggo
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.07.2009; Springer; Springer Nature B.V
• Subjects: Approximation; Automotive Engineering; Axial stress; Characterization and Evaluation of Materials; Chemistry and Materials Science; Civil Engineering; Classical Mechanics; Collapse; Contact pressure; Contact stresses; Cracks; Elongation; Exact sciences and technology; Failure analysis; Fracture mechanics (crack, fatigue, damage...); Fundamental areas of phenomenology (including applications); Hydrostatic pressure; Inelasticity (thermoplasticity, viscoplasticity...); Materials Science; Mathematical models; Mechanical Engineering; Microcracks; Original Paper; Physics; Plane strain; Plastic flow; Shear; Shear stress; Solid mechanics; Static elasticity (thermoelasticity...); Strain analysis; Stresses; Structural and continuum mechanics; Voids; Voids; Large strains; Plasticity; Shear deformation; Contact; Stress analysis; Microcrack; Plastic flow; Rupture; Frictionless contact; Transverse load; Cavitation; Modeling; Triaxial stress; Cavity; Contact stress; Hydrostatic pressure; Plane strain; Ductile material; Fracture surface
• ISSN: 0376-9429; 1573-2673
• DOI: 10.1007/s10704-009-9364-1

When voids are present in a ductile material subject to a shear dominated stress state under low stress triaxiality the voids collapse to micro-cracks, which subsequently rotate and elongate in the shear field. In the present plane strain analyses for cylindrical voids a surface load normal to a plane connecting the ends of the micro-crack is used as an approximate representation of contact stresses during frictionless sliding. In a previous study of the same problem the author applied hydrostatic pressure inside the nearly closed micro-crack to approximate contact conditions. The transverse surface loads used in the present analyses avoid the tendency to unrealistically elongate the voids. It is found that even though the model applied here gives significantly later occurrence of a maximum overall shear stress than that found by using hydrostatic pressure, the present model does predict a maximum in all the cases analyzed and thus illustrates the micro-mechanism leading to failure of the material by localization of plastic flow.