**1.2 Brittle failure in a material such as glass, rubber occurs due to the following reasons**


When a solid or structure has a geometrical discontinuity on the scale of the structure, its behavior can be described by the theories of fracture mechanics [2]. In two-dimensional media (such as plates and shells), the discontinuity features can take the shape of lines, whereas in three-dimensional media (such as spheres and cubes), the discontinuities can take the form of surfaces. Now a fully developed field of study,

fracture mechanics has revolutionized our understanding of how engineering materials behave. Fracture mechanics has had a major influence by introducing a new design philosophy, damage tolerance design methodology, which is now the gold standard in aviation design.
