%0 Journal Article %1 Tvergaard1990 %A Tvergaard, Viggo %D 1990 %J Advances in Applied Mechanics %K Charpy Localization V-notch bands; between crack different ductile flow; growth; interaction material material; model nucleation of plastic porous rate rounded sensitivity; shear size-scales strain studies; surface; test} vertex; voids; yield {cell %P 83-151 %T Material failure by void growth to coalescence %V 27 %X The porous ductile material models accounting for the nucleation and growth of voids are discussed in some detail, and cell model studies that are a major tool in understanding material behaviour are considered. Such model studies have been used to investigate the nucleation of voids and void coalescence, as well as the interaction between different size- scales of voids. Applications of the material model to predict fracture mechanisms in structural components or test specimens is one of the main purposes of developing these constitutive relations. Localization of plastic flow in shear bands leading to final shear fracture by a void-sheet mechanism is one such application, and ductile crack growth by void coalescence is another. Extensions of porous ductile material models to account for the effect of a rounded vertex on the yield surface or material strain rate sensitivity are presented. The viscoplastic material model used to represent rate sensitivity is illustrated by analyses of the fracture mode transition in the Charpy V-notch test. \par Void growth and coalescence is also the dominant cause of failure in polycrystalline metals subject to creep at elevated temperatures. However, at high temperatures the voids appear mainly in the grain boundaries, and diffusion gives a significant contribution to the growth rate. Due to the interaction of diffusion and dislocation creep, the rate of void growth can here be constrained by creep. This rather different mode of material failure by void coalescence is described in terms of a material model proposed by the author Acta Metall. 32, 1977-1990 (1984). Applications of the model to analyzes of creep rupture in structural components are included in the discussion.

@article{Tvergaard1990, abstract = {{The porous ductile material models accounting for the nucleation and growth of voids are discussed in some detail, and cell model studies that are a major tool in understanding material behaviour are considered. Such model studies have been used to investigate the nucleation of voids and void coalescence, as well as the interaction between different size- scales of voids. \par Applications of the material model to predict fracture mechanisms in structural components or test specimens is one of the main purposes of developing these constitutive relations. Localization of plastic flow in shear bands leading to final shear fracture by a void-sheet mechanism is one such application, and ductile crack growth by void coalescence is another. Extensions of porous ductile material models to account for the effect of a rounded vertex on the yield surface or material strain rate sensitivity are presented. The viscoplastic material model used to represent rate sensitivity is illustrated by analyses of the fracture mode transition in the Charpy V-notch test. \par Void growth and coalescence is also the dominant cause of failure in polycrystalline metals subject to creep at elevated temperatures. However, at high temperatures the voids appear mainly in the grain boundaries, and diffusion gives a significant contribution to the growth rate. Due to the interaction of diffusion and dislocation creep, the rate of void growth can here be constrained by creep. This rather different mode of material failure by void coalescence is described in terms of a material model proposed by the author [Acta Metall. 32, 1977-1990 (1984)]. Applications of the model to analyzes of creep rupture in structural components are included in the discussion.}}, added-at = {2009-08-01T18:40:48.000+0200}, author = {Tvergaard, Viggo}, biburl = {https://www.bibsonomy.org/bibtex/2a54b5800057b86a11ce0f16299b19706/jaksonmv}, classmath = {{*74R99 (Fracture and damage) 74C99 (Plastic materials, etc.) 74C15 (Large-strain, rate-independent theories) 74C20 (Large-strain, rate-dependent theories) }}, interhash = {4b9b0f6b9efed695a92471a732ae836b}, intrahash = {a54b5800057b86a11ce0f16299b19706}, journal = {Advances in Applied Mechanics}, keywords = {Charpy Localization V-notch bands; between crack different ductile flow; growth; interaction material material; model nucleation of plastic porous rate rounded sensitivity; shear size-scales strain studies; surface; test} vertex; voids; yield {cell}, language = {English}, pages = {83-151}, timestamp = {2009-08-01T18:40:58.000+0200}, title = {Material failure by void growth to coalescence}, volume = 27, year = 1990 }