fracture

A compliantly fixed hemispherical indenter in adhesive contact with an elastic sample firmly bonded to a rigid base is considered under the assumption that the rigid base undergoes small-amplitude high-frequency normal (vertical) oscillations. A general law of the rate-dependent JKR-type adhesion is assumed, which relates the work of adhesion to the contact front velocity. Using the Bogoliubov averaging approach in combination with the method of harmonic balance, the leading-order asymptotic model is constructed for steady-state vibrations.

I am happy to announce that a postdoctoral fellowship is available in the Dolbow Research Group at Duke University, working in the area of computational fracture mechanics.  The fellowship provides the opportunity to work on an emerging class of complete fracture models that incorporate the three ingredients that are necessary to be predictive with elastic brittle materials: their elasticity, their fracture toughness, and their strength.  

by Oscar Lopez-Pamies, John E. Dolbow, Gilles A. Francfort, and Chris J. Larsen

Abstract

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

I am deeply saddened by the passing of Andre Pineau in Paris yesterday. I happened to be one of ~100 PhD students he graduated over the course of his career.

EMI/PMC 2024, Chicago, IL, 2024 – MiniSymposium #0103 “Mechanics of granular materials: Modeling and characterization”

We are seeking a highly talented and motivated researcher to work within our strong research group “Dynamics of material fracture” oriented at experimental and numerical investigation of mechanical response and failure of materials at high strain rates. This post is based in Prague, Czech Republic and is available for 2 years.

The detailed description how-to apply for the position and the application form can be found here:

https://international.cvut.cz/jobs-at-ctu/postdoc/