Breaking phenomena brittle fracture

The occurrence of yam breaks was reported early and is connected with thickness fluctuations in extruded ribbons or films, as described collectively by the phenomenon of draw resonance , which is characterized by oscillations of the fiber diameter, which ultimately lead to yarn break. The latter is defined as brittle fracture and is thus related to melt temperature, molecular weight, quenching conditions, and particularly to the role of viscoelasticity, as described in the following section. 

In the case of silicate glasses, which break in a brittle manner, the fracture is time dependent. That is, for a given load, the fracture takes place after a period of time. This phenomenon is called static fatigue. The hme to failure is related to the fracture stress by the following equation ... 

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