• Ductile-to-brittle transition is simulated combining complete Gurson model and CZM. Brittle fracture only occurs when the ratio between cohesive strength yield below a critical value. Hydrogen embrittlement studied using this numerical framework hydrogen concentration revealed. A general simulation for modelling ductile-to-brittle in metals proposed. The method combines zone model, which brin...

We develop a reliable a posteriori anisotropic first order estimator for the numerical simulation of the Francfort and Marigo model of brittle fracture, after its approximation by means of the Ambrosio-Tortorelli variational model. We show that an adaptive algorithm based on this estimator reproduces all the previously obtained well-known benchmarks on fracture development with particular atten...

A model for mode I fracture in brittle materials is used to elucidate the relationship between characteristics of the fracture process, such as crack roughness, fractal dimension, and fragment size distributions. It is shown that different roughness in local regions of the crack path leads to different mechanisms for the subsequent fracture of those regions. Formation of two robust power laws f...

Experiments in brittle, amorphous PMMA indicate that the process of dynamic fracture is governed by a micro-branching instability. At a critical velocity, vc, a single crack undergoes an abrupt, well-defined transition to microscopic crack branching. As a result, the velocity of the crack develops oscillations, the mean acceleration decreases and structure is formed on the fracture surface. Bey...

When a cylindrical tool cuts through a thin sheet of a relatively brittle material, it leaves behind a visually arresting crack street in its wake, reminiscent of a vortex street in the wake of a cylinder moving through a fluid. We show that simple geometrical arguments based on the interplay of in-plane stretching and out-of-plane bending suffice to explain the cycloidal morphology of the curv...

CoSb3 based skutterudite thermoelectric material has superior thermoelectric properties, but the low fracture toughness prevents its widespread commercial application. To determine the origin of its brittle failure, we examined the response of shear deformation in CoSb3 along the most plausible slip system (010)/<100>, using large-scale molecular dynamics simulations. We find that the brittle f...

This in vitro study examined the effect of surface defects on cutting blades on the extent of the cyclic fatigue fracture of HEROShaper Ni-Ti rotary files using fractographic analysis of the fractured surfaces. A total of 45 HEROShaper (MicroMega) Ni-Ti rotary files with a #30/.04 taper were divided into three groups of 15 each. Group 1 contained new HEROShapers without any surface defects. Gro...