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...

Water molecules play a fundamental role in the physics of slow crack propagation in glasses. It is commonly understood that, during stress-corrosion, water molecules that move in the crack cavity effectively reduce the bond strength at the strained crack tip and, thus, support crack propagation. Yet the details of the environmental condition at the crack tip in moist air are not well determined...

A B S TR AC T This paper presents an incremental elastic-plastic finite element solution to the problem of small scale yieldmg near a crack in plane strain for a non-hardening material. Emphasis is placed on the design of finite elements which allow accurate reproduction, m a numerical solution, of the detailed structure of the near crack tip stress and strain fields, as understood from previou...

Age-hardenable aluminum alloys used in aerospace structures are susceptible to environment assisted fatigue crack propagation (EFCP), limiting component durability and safety. The objective is to quantitatively understand EFCP and its inhibition for important aerospace alloys: 7075-T651 (Al-Zn-Cu-Mg), C433-T3 (Al-Cu-Mg), and C47A-T86 (AlCu-Li). EFCP is understood through the hydrogen embrittlem...

This paper presents a finite element formulation of elasticity to model elastic fracture in composites with long aligned fibers. We have employed a B-bar type approach which is applicable to compressible as well as nearly incompressible material systems. An energy approach is undertaken to evaluate the stress intensity factor at the crack tip. The effects of strong intact bridging fibers, fiber...

A nonlinear elastic foundation model has been developed to predict the mixed-mode (modes I and II) delamination failure of laminated composites. Two types of nonlinear elastic foundations were used to represent pure mode I and pure mode II components of the material failure ahead of the crack tip. One is a tension spring foundation for mode I component and the other is a shear spring foundation...

This letter describes a newly discovered phenomenon: ductile fracture in cementitious materials. The brittle nature of materials such as concrete and ceramics has prompted the development of various approaches to enhance their fracture toughness. Fibre reinforcement has been the common focus in the toughening of the brittle materials. Two types of fracture have been observed to date in cementit...

In this work, a combination of digital image correlation and high-speed photography is used to study mixed-mode dynamic fracture in syntactic foams under stress wave loading conditions. Edge cracked foam samples are subjected to mixed mode loading by impacting eccentrically relative to the initial crack plane in three point bend configuration. Ultra high-speed CCD digital camera is used to reco...