Surface stress relaxation and resulting residual stress in glass fibers: A new mechanical strengthening mechanism of glasses

► Permanent bending kinetics of glass fibers were analyzed in terms of surfaces stress relaxation and residual stress. ► The fiber bending kinetics were found to be controlled by water diffusion into the glass surface. ► The surface stress relaxation and the resultant residual stress can be used for strengthening of glasses. ► This strengthening process can be used for thin specimens as well as for alkali-free glasses.