A fracture is the separation of a body into two, or more, pieces under the action of stress.

The word fracture is often applied to bones of living creatures, or to crystals or crystalline materials, such as gemstones or metal. Sometimes, in crystalline materials, individual crystals fracture without the body actually separating into two or more pieces. Depending on the substance which is fractured, a fracture reduces strength (most substances) or inhibits transmission of light (optical crystals).

A detailed understanding of how fracture occurs in materials requires the study of fracture mechanics.

Types of fracture

Shear fracture arises from the action of shear stress and slip in crystals. Alternatively, cleavage fracture is the result of tensile stress acting normal to a crystal's cleavage plane.

In brittle fracture, no plastic deformation takes place before fracture. In ductile fracture, extensive plastic deformation takes place before fracture.

Bibliography

• Dieter, G. E. (1988) Mechanical Metallurgy ISBN 0071004068
• A. Garcimartin, A. Guarino, L. Bellon and S. Cilberto (1997) " Statistical Properties of Fracture Precursors ". Physical Review Letters, 79, 3202 (1997)