http://dx.doi.org/10.1016/j.actamat.2015.07.022 1359-6454/ 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. ⇑ Corresponding author at: Department of Materials Science & Engineering, University of California, Berkeley, CA 94720, USA. E-mail address: [email protected] (R.O. Ritchie). 1 Intrinsic toughening mechanisms operate ahead of the crack tip to resistance to microst...

Large scale simulations using cohesive zone interfacial elements were used to understand features such as penetration and deflection of crack during the process of interaction of mode-I crack with inclined interfaces. To perform these simulations, two set of inputs are necessary. The first one is to provide valid loading boundary conditions and the second one is to incorporate accurate cohesive...

This article discusses results obtained from a parametric study to analytically evaluate the impingement of a crack at the interface of an environmental barrier coating (EBC) and a monolithic Silicon nitride (Si 3 N 4) layered ceramics substrate. The study establishes a correlation that leads to determine if the crack is arrested or advanced by either penetrating or deflecting along the EBC/sub...

Over the past decades, our understanding of nacre's toughening origin has long stayed at the level of crack deflection along the biopolymer interface between aragonite platelets. It has been widely thought that the ceramic aragonite platelets in nacre invariably remain shielded from the propagating crack. Here we report an unexpected experimental observation that the propagating crack, surprisi...

Multi-layered bearing systems used in the automotive industry show shielding and antishielding effects that reduce or amplify the crack driving force under large scale yielding conditions. Using finite element analysis, it is shown that shielding in such systems results in path deflection and bifurcation despite the absence of mixed-mode loading. As the crack approaches a stiff layer, the tange...

Bamboo, as a natural hierarchical cellular material, exhibits remarkable mechanical properties including excellent flexibility and fracture toughness. As far as bamboo as a functionally graded bio-composite is concerned, the interactions of different constituents (bamboo fibers; parenchyma cells; and vessels.) alongside their corresponding interfacial areas with a developed crack should be of h...

The evolution of the crack growthspeed in a thin, buckled strip delamina-tion is studied and two approximate solu-tions are presented. The quasi-dynamicanalysis assumes that the deflection ofthe delaminated layer is represented bythe static postbuckling solution for thecurrent delamination length. A refinedanalysis introduces an indeterminateamplitude functio...

Experimental study on the influence of fibre content on crack behaviour and propagation in synthetic-fibre reinforced beams has been reported in this paper. The tensile behaviour of metallic fibre concrete is evaluated in terms of residual flexural tensile strength values determined from the load-crack mouth opening displacement curve or load-deflection curve obtained by applying a centre-point...

In this paper, we report on an experimental study of the deflection/penetration behavior of dynamic mode-I cracks propagating at two different crack velocities (slower and faster) toward inclined weak interfaces of three dissimilar angles (a): 30 , 45 and 60 . A simple wedge-loading specimen configuration as proposed by Xu et al. [Xu LR, Huang YY, Rosakis AJ. Dynamic crack deflection and penetr...

Pangolin scales form a durable armor whose hierarchical structure offers an avenue towards high performance bio-inspired materials design. In this study, the fracture resistance of African pangolin scales is examined using single edge crack three-point bend fracture testing in order to understand toughening mechanisms arising from the structures of natural mammalian armors. In these mechanical ...