No abstract

Molecular dynamic calculations of the structure of a series of sodium silicate glasses, a common soda–lime glass, a sodium borosilicate glass and a sodium–potassium silicate glass were made. Calculated radial distribution functions are in good agreement with existing x-ray diffraction data and a previous MD calculation on silica glass. During the dynamical runs alkali and alkaline earth cations cluster around nonbridging oxygen atoms. In the borosilicate glass studied, the boron atoms enter the silica network and are tetrahedrally coordinated by oxygen. Other features of the simulated glasses include the coordination number of cations, the degree of inhomogeneity, the distribution of bridging and nonbridging oxygen atoms, the Si–O–Si bond angles, the ring structure, etc. Some preliminary diffusion studies will be presented.

Using the finite-element program MARC developed by MARC Analysis Corporation, thermal stresses are calculated for a simple sandwich seal and a bead seal under conditions of uniform cooling, reheating, and an isothermal hold and for a tempered glass plate. Results of the viscoelastic calculations are compared with previously obtained analytical solutions and with experimental stress measurements. The formalism for including viscoelastic material properties in the program is developed.

The purpose of this paper is to compare simple and efficient pairwise force fields for silica glass and assess their applicability for use in large

No abstract