Stress enhancement in the vicinity of brittle cracks makes the macro-scale failure properties extremely sensitive to the micro-scale material disorder. Therefore: (i) Fracturing systems often display a jerky dynamics, socalled crackling noise, with seemingly random sudden energy release spanning over a broad range of scales, reminiscent of earthquakes; (ii) Fracture surfaces exhibit roughness a...

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 ...

Abstract Brittle materials are widely used for producing important components in the industry of optics, optoelectronics, and semiconductors. Ultraprecision machining brittle with high surface quality integrity helps improve functional performance lifespan components. According to their hardness, can be roughly divided into hard-brittle soft-brittle. Although there have been some literature rev...

Three principal methods used to study stresses in materials are photoelastic stress analysis, brittle lacquer-coating techniques, and electronic strain gauges. A number of studies have been conducted using models and the photoelastic method' to examine stress patterns in oneand two-surface inlays, complete dentures, teeth and supporting bone, and rests used in partial dentures. Strain gauges4 9...

The purposes of this investigation were to determine the effect of nitrogen on the strain aging and brittle ductile transition of iodide vanadium and to determine the basic mechanisms responsible for the occurrence of these results. Disciplines Ceramic Materials | Metallurgy | Other Materials Science and Engineering This report is available at Iowa State University Digital Repository: http://li...

We present an experimental study of the dynamics of rapid tensile fracture in brittle amorphous materials. We first compare the dynamic behavior of “standard” brittle materials (e.g. glass) with the corresponding features observed in “model” materials, polyacrylamide gels, in which the relevant sound speeds can be reduced by 2-3 orders of magnitude. The results of this comparison indicate unive...

The problem of dynamic symmetric branching of a tensile crack propagating in a brittle material is studied within Linear Elastic Fracture Mechanics theory. The Griffith energy criterion and the principle of local symmetry provide necessary conditions for the onset of dynamic branching instability and for the subsequent paths of the branches. The theory predicts a critical velocity for branching...

We present a variational model to study the quasistatic growth of brittle cracks in hyperelastic materials, in the framework of finite elasticity, taking into account the non-interpenetration condition.