If the metal and the surrounding glass are symmetric the crack propagates in an angle away from the axis.

Very often one finds a single crack has propagated while the rest of the metal surface stays apparently unaffected.

The crack would propagate slowly across the ever-changing stress field, describing an arc.

Then, in a single, abrupt instant, cracks propagated across the walls.

This ultimate failure is definite since the crack will propagate on its own once the length is greater than 2a.

The cracks propagated with each new experimental assignment in counter-intelligence.

The crack may propagate in the center of the layer or near an interface.

The manner through which the crack propagates through the material gives great insight into the mode of fracture.

The subcritical nature of propagation may be attributed to the chemical energy released as the crack propagates.

This separation of cement particles causes the entire structure to fail as crack propagates.