A creep rupture model accounting for cavitation at sliding grain boundaries

Abstract

Link to publication in University of Groningen/UMCG research database Citation for published version (APA): Giessen, E. V. D., & Tvergaard, V. (1991). A creep rupture model accounting for cavitation at sliding grain boundaries. International Journal of Fracture, 48(3). DOI: 10.1007/BF00036629 Copyright Other than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum. Abstract. An axisymmetric cell model analysis is used to study creep failure by grain boundary cavitation at facets normal to the maximum principal tensile stress, taking into account the influence of cavitation and sliding at adjacent inclined grain boundaries . It is found that the interaction between the failure processes on these two types of adjacent facets reduces the failure time significantly when cavitation is creep constrained . In all cases the time to cavity coalescence on transverse facets appears to be a useful lower bound measure of the material life-time . Sliding at the boundaries of the central grain of the cell model is accurately represented ; but in some computations a stress enhancement factor is used to incorporate also the effect of sliding between surrounding grains . The influence of grain boundary viscosity is included in the model and it is found that even in the absence of sliding, cavitation on inclined boundaries may significantly reduce the failure time .

Numerical simulation of grain-size effects on creep crack growth by means of grain elements

“…The increase in Ė / ε·B indicates that the strain rate contribution of grain boundary sliding decreases with increasing grain size, which agrees with experimental observations [2,10]. However, the effect on the overall strain rate is rather small [18]. The decrease in ad L indicates that the relative contribution of diffusion to cavity growth increases (see Sec.…”

“…Therefore, as in [16,17,18,19], we assume that the material inside the grains is homogeneous and isotropic, and that creep is described by the power law based on average properties.…”

A Generalized Finite Element Method for polycrystals with discontinuous grain boundaries

“…Comparing the above with (2), we have that Equation (10) shows that the global approximation u h (x) is built by pasting together local approximations u h , = 1, . .…”

“…There are no limitations on grain shape and the number of grain boundaries meeting at a junction, and any grain boundary behaviour can be handled [10][11][12]. There is however a range of situations where the boundaries of grains in polycrystals have a significant influence on the overall deformation and fracture behaviour.…”

Interaction of cavitating grain boundary facets in creeping polycrystals

“…Either a single cavitating facet or a periodic array of cavitating facets have been conCorrespondence to: Prof. V. Tvergaard, The Technical University of Denmark, Department of Solid Mechanics, Building 404, DK-2800 Lyngby, Denmark. sidered (Rice, 1982;Tvergaard, 1984), and some studies have also incorporated the effect of grain boundary sliding on the rate of nucleation and growth of grain boundary cavities (Anderson and Rice, 1985;Tvergaard, 1985;Van der Giessen and Tvergaard, 1991a). Axisymmetric model problems have been considered in most of these analyses, to obtain a reasonably realistic approximation of the real three-dimensional facet geometry, but still avoiding a full 3D analysis.…”