Atomic-Level Fluctuation Mechanism of the Fracture of Solids (Computer Simulation Studies)

Breaking stress of neutron star crust

“…For most terrestrial materials, the durability (time before breaking) τ at a given stress is known to depend on the temperature and, of course, the applied stress (e.g. Zhurkov 1957; Regel', Slutsker & Tomashevskii 1972; Slutsker 2004, 2005; Slutsker et al 2007). In other words, the breaking stress is not just a constant, defined by the matter parameters (density, temperature and composition), but depends on the duration of the stress – the matter can break at lower stress, if one waits long enough.…”

A study of the fracture mechanisms in pristine silica fibres utilising high speed imaging techniques

“…The fluctuation in the kinetic energy of the molecules can lead to extension of the bond and loss of cohesion [64,66]. The resulting defects can migrate through the solid and combine into clusters.…”

“…The coefficient γ has dimensions of volume and is sometimes described as the activation volume. The activation volume depends on the local over-stress in a test sample [66]. The speed of the crack growth is described by a formula with the same exponential factor as above; at large stresses the speed at which the defects assemble can become close to the speed of sound in the material and in this case the defect formation is catastrophically quick [64,67].…”

“…The resulting defects can migrate through the solid and combine into clusters. The process of the defect assembly is responsible for the "lifetime of a macroscopic test sample", τ, that can be described by the empirical formula [65,66,64]:…”

“…The model which is used to describe the fracture of brittle materials [62,63] is based on the thermo-kinetic theory [64][65][66][67] of solid fracture. This model states that the formation of defects is caused by thermal fluctuations in the kinetic energy of the atoms.…”