An increased incidence of fracture has been reported in teeth where root canals were treated with calcium hydroxide. Edge chipping is one test used to measure the resistance of brittle materials to fracture. Presently, no studies have reported on edge chipping in teeth. This study evaluated the fracture resistance of human dentin exposed to calcium hydroxide for up to 60 days using the edge chi...

It has long been observed that brittle fracture of materials can lead to emission of high energy electrons and UV photons, but an atomistic description of the origin of such processes has lacked. We report here on simulations using a first-principles-based electron force field methodology with effective core potentials to describe the nonadiabatic quantum dynamics during brittle fracture in sil...

We describe experiments on the dynamic fracture of the brittle plastic, PMMA. The results suggest a view of the fracture process that is based on the existence and subsequent evolution of an instability, which causes a single crack to become unstable to frustrated microscopic branching events. We demonstrate that a number of long-standing questions in the dynamic fracture of amorphous, brittle ...

In this paper the Discrete Element Model (DEM) ‘ESyS_Particle’, previously used to model fracture of brittle rocks and earthquake processes, is further developed to be able to be applied to the hydraulic fracturing process in Engineered Geothermal Systems (EGS). The advantage of DEM is that large deformations and dynamic process can be modelled easily. ESyS_Particle has been used to successfull...

At low temperatures silicon is a brittle material that shatters catastrophically, whereas at elevated temperatures, the behavior of silicon changes drastically over a narrow temperature range and suddenly becomes ductile. This brittle-to-ductile transition has been observed in experimental studies, yet its fundamental mechanisms remain unknown. Here we report an atomistic-level study of a funda...

Structural design with brittle materials requires that the stress level in the component correspond to a material survival probabi 1 i ty that exceeds the minimum survival probability permitted in that application. This can be achieved by developing failure models that fully account for the probability of fracture from defects within the material (including considerations of fracture statistics...

The fracture toughness and strength of ceramics can be improved with respect to monolithic ceramics by developing graded materials as laminates composed of periodic alternating layers of one material separated by layers of a second material. The second layer must contain residual compressive stresses which are induced during densification because of differential thermal contraction of the layer...

PCB assembly and handling operations involving excessive monotonic bending at high strain rates can cause brittle solder joint failures in BGA packages. This paper deals with brittle fracture of flip-chip BGA packages with electroless Nickel immersion Gold (ENIG) substrate pad finish. A high speed 4-point bend test has been used to evaluate the flexural strength of different component sizes and...

Recent work at the Underground Research Laboratory of Atomic Energy of Canada Limited in Pinawa, Manitoba, has shown that high compressive stresses near the tunnel face significantly contribute to the loss of strength, and eventual failure of the rock, through stress-induced brittle fracturing. A program of laboratory testing has been undertaken to investigate the effects of brittle fracture on...

The mixed brittle–plastic fiber bundle model is an extension model based on the classical fiber bundlemodel to describe the nonbrittle failure process of some hierarchical structure materials such as spider silk. In order to explore the breaking dynamic properties of the hierarchical structure materials in short-range correlation, the mixed brittle–plastic fiber bundle model in local load shari...