The problem of dynamic symmetric branching of a tensile crack propagating in a brittle material is studied within Linear Elastic Fracture Mechanics theory. The Griffith energy criterion and the principle of local symmetry provide necessary conditions for the onset of dynamic branching instability and for the subsequent paths of the branches. The theory predicts a critical velocity for branching...

The high cycle fatigue (HCF) cracking behaviors in the SnPb solder joints were investigated experimentally via in situ observations with scanning electron microscope (SEM). The results indicate that the HCF cracks incubate at the toe of the solder joints and propagate mainly along an angle from 20 to 45 tilted to the applied stress axis differing greatly from the propagation behaviors reported ...

In dentistry, many preparation guidelines for allceramic crowns are still based upon clinical experience and those developed for metal ceramic crowns that may not be applicable and need further experimental and numerical evaluation. Some specific features are requiring investigation in dental prosthetic devices, for example, configurations of the crowns’ margin [1], marginal thickness [2, 3] an...

Y. Hu*, N.K. Kar andS.R. Nutt Gill Composites Center, Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California Abstract: The mechanical response of unidirectional composites subject to uniaxial transverse compressive loads was measured and analyzed by finite element simulation. Consistency in failure plane orientation was observed when...

Aging aircraft may develop multiple-site damage (MSD) that can reduce the structural integrity of fuselage structures. The existence of small cracks emanating from adjacent rivet holes in a fuselage lap-splice joint is of major concern. Small collinear cracks greatly reduce the residual strength of a panel with a lead crack. Recent studies predicting the residual strength of flat and curvilinea...

The size and the character (low and large angle, special boundaries, tilt and twist boundaries, twins) of the grain boundaries (GBs) in polycrystalline materials influence their strength and their fracture toughness. Recent studies devoted to nanocrystalline (NC) materials have shown a deviation from the Hall-Petch law. Special GBs formed by Σ3 twins in face-centred cubic metals are also known ...

Endovascular stents made of the superelastic nickel-titanium alloy Nitinol are subjected in service to tens of millions of loading cycles and even "single-event" overloads, both of which can potentially result in fracture and/or complete failure of the device. A fracture-mechanics-based methodology can provide a means to quantify relevant material parameters critical to the design against such ...

Traction–separation relations can be used to represent the adhesive interactions of a bimaterial interface during fracture. In this paper, a direct method is proposed to determinemixed-mode traction– separation relations based on a combination of global and local measurements including load-displacement, crack extension, crack tip opening displacement, and fracture resistance curves. Mixed-mode...

the prevalent method of irrigation in paddy fields in iran is continuous ponding, which changes to intermittent method at the time of water shortage. soil cracks are the main problem in intermittent irrigation. in this study, effects of adding rice straw on some soil physical characteristics and cracks were studied in paddy soils of the guilan province of iran. the experiment was performed as s...

in this paper, the experimental method of caustics and its application to stress field and related studies in fracture mechanics is described. theocaris [1,2,3] has used the optical method of caustics to study stress intensity factors and the stress field around crack tips, in cracked transparent plates. many other researchers have also used this method to obtain stress intensity factors for di...