Aug. 22 (UPI) -- Scientists at Lomonosov Moscow State University have uncovered the secrets behind the critical stage of fracture in rock destruction.
The researchers revealed a criterion that can help predict the stage of fracture when rock destruction occurs and determine the stages of deformation are different in the character of defect accumulation inside rocks.
"At first defects are generated randomly and their size is determined by a typical structural element of a material [for instance, a grain in granite], Dmitry Korost, of the Lomonosov Moscow State University Scientific Training Center, said in a news release.
"Afterwards there is the turn for generation of such defects, whose sizes are not determined by the material structure. Interaction between these two defect types causes critical defects, capable of self-development. By all appearances, the loss of sample integrity occurs as a result of the evolution of a set of critical defects."
The study, published Monday in Interpretation, found that deformation stages can be distinguished by the type of energy distribution of acoustic emission, an inspection technique for material integrity, signals.
Acoustic emission is measured by recording elastic waves and energy distribution is approximated by different types of functions.
Researchers studied the destruction of rocks using acoustic emission and X-ray computer tomography.
"The revealed criterion could become useful in various situations: appraising the state of structures under load or the state of a rock massif at an operating mining venture," researchers wrote. "It's also applicable for earthquake forecasting. The criterion also allows to detect the space domain of an object, where localization of defect formation, leading to the object destruction, could occur."