In crystalline solids, ionic bonds transfer electrons between ions, typically breaking between 600 to 4000 kJ/mole. Glass covalent bond breakage energy is in the high range of 435 kJ/mole. Covalent bonds share electrons between atoms, typically breaking between 150 and 400 kilojoules per mole (kJ/mole).
Unlike solid material crystalline lattice structures with ionic bonds, such as ceramics, glass is an amorphous solid (i.e., not a supercooled fluid) relying on covalent bonds. An annealing process slowly cools the material to release internal stresses, resulting in the most common manufactured form of architectural flat glass. Heated to 1500 degrees Celsius, the mixture forms into a continuous ribbon “floated” on a long bath of liquid tin. Soda-lime silica flat glass sheets consist of silica sand, sodium carbonate, lime, metal oxides, and recycled glass. The objective is to provide information to engineers investigating glass breakage and tips for specifiers to avoid glass breakage problems. This article discusses basic fracture technology of flat glass in architectural and structural glass assemblies, illustrating characteristic fracture surfaces and crack patterns. The crack patterns in broken glass and their fracture surface details describe the origination and energy intensity that caused breakage.
0 kommentar(er)
