2-point bending strength of glass fibers

Failure strains of some glass fibers were measured by 2-point bending test at liquid nitrogen temperature. The failure strength was estimated from failure strain and Young's modulus of glass. At a face-plate rate of 50μm/sec, failure strains were 12% (failure strength is 8.6GPa) for silica glass, 15% (10GPa) for soda-lime glass and 16% (10GPa) for lead glass, respectively. High failure strength of lead glass fiber suggests that 2-point bending strength of glass fiber is determined not only from interatomic bond strength but also from inelastic energy dissipation on fracture. © 2008 The Society of Materials Science.