Densification dependent yield criteria for sodium silicate glasses – An atomistic simulation approach. (1st June 2016)

• Record Type: Journal Article
• Authors: Molnár, Gergely; Ganster, Patrick; Tanguy, Anne; Barthel, Etienne; Kermouche, Guillaume
• Is Part Of: Acta materialia. Volume 111(2016)
• Page Start: 129
• Page End: 137
• Publication Date: 2016-06-01
• Subjects: Silicate -- Constitutive modeling -- Yield strength -- Multiscale modeling -- Molecular statics; Materials -- Periodicals; Materials science -- Periodicals; Materials -- Mechanical properties -- Periodicals; Metallurgy -- Periodicals; Chemistry, Inorganic -- Periodicals; 620.112
• DOI: 10.1016/j.actamat.2016.03.053
• Languages: English
• ISSNs: 1359-6454

Abstract

Abstract: Silicate glasses are macroscopically brittle but ductile at the micron scale. This plastic response is complex: in open structure materials, such as amorphous silica, plastic yield results in significant densification. While, more compact structures (e.g. soda-silicate glasses) are known to suppress densification and promote shear flow. We have carried out atomic scale simulations to analyze the plastic response of a series of silicates with increasing sodium content. Quasi-static, multi-axial deformation tests were performed on large samples (≈10 3 nm 3 ). Their yield behavior was quantified at different stress states, by measuring permanent volume changes. Qualitative agreement was found between the response of modeled systems and experimental results. Strong coupling between plastic yield and densification was observed. Our results also suggest that sodium silicates may densify not only under hydrostatic compression but also upon shear at large strains. Based on these numerical results, we propose a general yield criterion for soda-silicate glasses in which density is an internal variable. As density increases, the elliptic yield surface (characterizing amorphous silicates with open structures) gradually evolves into a Drucker-Prager-like model for fully densified samples. Graphical abstract: