Supersonic fractures are fracture

Fracture

A fracture is the separation of an object or material 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...

s where the fracture velocity moves faster than the speed of sound

Speed of sound

The speed of sound is the distance travelled during a unit of time by a sound wave propagating through an elastic medium. In dry air at , the speed of sound is . This is , or about one kilometer in three seconds or approximately one mile in five seconds....

 in the material. This phenomenon was first discovered by scientists from the Max Planck Institute for Metals Research in Stuttgart (Markus J. Buehler

Markus J. Buehler

Markus J. Buehler is an American materials scientist and engineer at the Massachusetts Institute of Technology . He joined MIT in 2005 and is currently a faculty member in the Department of Civil and Environmental Engineering, where he directs the Laboratory for Atomistic and Molecular Mechanics...

 and Huajian Gao

Huajian Gao

Huajian Gao is an American materials scientist and engineer. He joined the Max Planck Society in 2001 and is currently Director of the Max Planck Institute for Metals Research, Stuttgart.-Education and career:...

) and IBM Almaden Research Center in San Jose, California (Farid F. Abraham

Farid F. Abraham

Farid F. Abraham is an American scientist.Abraham earned his Bachelor of Science and Ph.D from the University of Arizona in 1959 and 1962, respectively. By pioneering new methods of using computer modelling in research, he has made seminal contributions to science in the fields of fracture...

).

The issues of intersonic and supersonic fracture become the frontier of dynamic fracture mechanics

Fracture mechanics

Fracture mechanics is the field of mechanics concerned with the study of the propagation of cracks in materials. It uses methods of analytical solid mechanics to calculate the driving force on a crack and those of experimental solid mechanics to characterize the material's resistance to fracture.In...

. The work of Burridge initiated the exploration for intersonic crack growth (when the crack tip velocity V is between the shear in wave speed C^8 and the longitudinal wave speed C^1.