fractography

In this work, we show that the combination of material quenched disorder (of finite strength/amplitude and correlation length) and a 2D tip-splitting instability (that gives rise to extra fracture surfaces) is at the heart of the spatiotemporal dynamics of cracks in 3D. Specifically, it is shown to account for the widely observed limiting (terminal) velocity of cracks, mirror-mist-hackle sequence of morphological transitions, crack macro-branching and a 3D-to-2D transition, out-of-plane crack front waves and the properties of micro-branches.  

Following the previous Blog entry on 3D fracture and out-of-plane crack structures: the essential role of material disorder, we add here a related manuscript (see also attached PDF):

Size selection of crack front defects: Multiple fracture-plane interactions and intrinsic lengthscales

In this pair of preprints (see also attached PDFs):

Quenched disorder and instability control dynamic fracture in three dimensions

Facet formation in slow three-dimensional fracture

The transition between necking-mediated tensile failure of glasses, at elevated temperatures

and/or low strain-rates, and shear-banding-mediated tensile failure, at low temperatures and/or

high strain-rates, is investigated using tensile experiments on metallic glasses and atomistic simula-

tions. We experimentally and simulationally show that this transition occurs through a sequence of

macroscopic failure patterns, parametrized by the ultimate tensile strength. Quantitatively analyz-

Pectin’s unique physicochemical properties have been linked to a variety of reparative and regenerative processes in nature. To investigate the effect of water on pectin repair, we used a 5 mm stainless-steel uniaxial load to fracture glass phase pectin films. The fractured gel phase films were placed on a 1.5–1.8 mm thick layer of water and incubated for 8 h at room temperature and ambient humidity. There was no immersion or agitation. The repaired pectin film was subsequently assessed for its optical and mechanical properties.