A scale-linking, experimental study complemented by an analytical model was carried out to investigate the influence of fiber orientation on crack-opening behavior strain-hardening cement-based composites (SHCC). Three SHCC compositions were investigated with polyvinyl alcohol (PVA) and ultra-high molecular weight polyethylene (UHMWPE) fibers in combination normal- high-strength matrices. The m...

There are many ways that women support their use of crack cocaine, including sex-for-crack bartering and other forms of prostitution. Empirical studies conducted in the mid-1970s and in the mid-1980s in New York City, and in Chicago in the late 1980s to early 1990s are compared, analyzing similarities and differences between the contemporary crack-prostitution scene and previous prostitution sc...

It is well known that the near-tip displacement eld on a crack surface can be represented in a power series in the variable p r, where r is the distance to the tip. It is shown herein that the coe cients of the linear terms on the two sides of the crack are equal. Equivalently, the linear term in the crack opening displacement vanishes. The proof is a completely general argument, valid for an a...

The size-effect, two-parameter, and fictitious crack models were developed to predict crack growth in materials like concrete that experience tension softening. The three models must predict the same response for infinitely large structures. Therefore, this study evaluates the differences in response for smaller structures. The metric used to compare response is the fracture toughness value req...

To better understand the ductile versus brittle fracture behavior of crystalline materials, attention should be directed towards physically realistic crack geometries. Currently, continuum models of ductile versus brittle behavior are typically based on the analysis of a pre-existing sharp crack in order to use analytical solutions for the stress 8elds around the crack tip. This paper examines ...

The normal stress distribution across a slip plane has the effect of reducing the critical loading required for dislocation emission from a crack tip. The reduction by normal stresses was found to be very significant for Si, based on properties estimated for it using density functional theory, to be large for Fe as modeled by the embedded atom method (EAM), and to be smaller in AI, Ni and order...

This paper considers a 2-D fracture analysis of anisotropic piezoelectric solids by a boundary elementfree method. A traction boundary integral equation (BIE) that only involves the singular terms of order 1/r is first derived using integration by parts. New variables, namely, the tangential derivative of the extended displacement (the extended displacement density) for the general boundary and...

This paper reviews some of the advances that have been made in stress analyses of cracked aircraft components, in the understanding of the fatigue and fatigue-crack growth process, and in the prediction of residual strength of complex aircraft structures with widespread fatigue damage. Finite-element analyses of cracked structures are now used to determine accurate stress-intensity factors for ...

A line integral is exhibited which has the same value for all paths surrounding the tip of a notch in the two-dimensional strain field of an elastic or deformation-type elastic-plastic material. Appropriate integration path' choices serye bOlh to relate Ihe integral to the near tip deformatiot~s and, in many cases. to permit its direct e:tlalutllion. This (l.t'eraged measure of the near tip fie...