Some practical crack path examples

It is well known that many engineering structures and components, as well as consumer items,

contain cracks or crack-like flaws. It is widely recognised that crack growth must be considered both in design

and in the analysis of failures. The complete solution of a crack growth problem includes determination

of the crack path. Macroscopic aspects of crack paths have been of industrial interest for a very long time.

At the present state of the art the factors controlling the path taken by a crack are not completely understood.

Eight brief case studies are presented. These are taken from the author’s professional and personal experience

of macroscopic crack paths over many years. They have been chosen to illustrate various aspects of

crack paths. One example is in a component from a major structure, three examples are in laboratory specimens,

and four are in nuisance failures. Such nuisance failures cause, in total, a great deal of inconvenience

and expensive, but do not normally receive much publicity.