Evidence has accumulated recently that a crack can propagate on an interface between dissimilar solids at speeds between the smallest and the largest sonic speeds of the constituent solids. Such an intersonic crack has posed several challenges to the existing theory. Assuming that the crack tip is a structureless point, and the solids are linearly elastic all the way to the crack tip, the theor...

In previous studies, enamel showed indications to occlude small cracks in-vivo and exhibited R-curve behaviors for bigger cracks ex-vivo. This study quantifies the crack tip's toughness (K(I0),K(III0)), the crack's closure stress and the cohesive zone size at the crack tip of enamel and investigates the toughening mechanisms near the crack tip down to the length scale of a single enamel crystal...

This paper (Part II), which is the second in a series of two papers, presents new closed-form solutions for net-section-collapse (NSC) analysis of circumferentially cracked pipes for several idealized crack shapes subjected to combined bending and tension (pressure-induced) loads. They are based on further simpli®cations of generalized NSC equations developed in a parallel study. Analytical sol...

Rate effects for adhesively-bonded joints in steel sheets failing by mode-I fracture and plastic deformation were examined. Three types of test geometries were used to provide a range of crack velocities between 0.1 mm/s and 5000 mm/s: a DCB geometry under displacement control, a wedge geometry under displacement control, and a wedge geometry loaded under impact conditions. Two fracture modes w...

16 This paper presents a novel large-area strain sensing technology for monitoring fatigue cracks in 17 steel bridges. The technology is based on a soft elastomeric capacitor (SEC), which serves as a 18 flexible and large-area strain gauge. Previous experiments have verified the SEC’s capability to 19 monitor low-cycle fatigue cracks experiencing large plastic deformation and large crack openin...

The effects of loading conditions, specimen size and metal particle size on the crack growth resistance curve (R-curve) and residual strength of a ceramic-metal functionally graded material (FGM) are studied based on the crack-bridging concept. It is found that the FGM exhibits strong R-curve behavior when a crack grows from the ceramic-rich region toward the metal-rich region and the residual ...

Fretting fatigue induced by combined localized cyclic contact motion and external bulk fatigue loadings may result in premature and dramatic failure of the contacting components. Depending on fretting and fatigue loading conditions, crack nucleation and possibly crack propagation can be activated. This paper proposes a procedure for estimating these two damage thresholds. The crack nucleation b...

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...

Centrifugal compressors are a key piece of equipment for modern production. Among the components of the centrifugal compressor, the impeller is a pivotal part as it is used to transform kinetic energy into pressure energy. Blade crack condition monitoring and classification has been broadly investigated in the industrial and academic area. In this research, a pressure pulsation (PP) sensor arra...

Cracking and fracture of electrodes under diffusion during lithiation and delithiation is one of the main factors responsible for short life span of lithium based batteries employing high capacity electrodes. Coupling effects among lithium diffusion, stress evolution and crack propagation have a significant effect on dynamic processes of electrodes during cycling. In this paper, a phase field m...