The article shows the effect of torsional rigidity of beam elements onto spatial work of bridges, floorings and other plate-ribbed systems It is shown that, in determining the torsional rigidity using existing methods it is necessary to have spatial spiral cracks, but torsional rigidity when normal cracks is not researched. A method is described for determining the torsional rigidity of reinfor...

conclusions regarding the study limitations, dentinal cracks were observed in all files and distances from the apex. although there was more crack incidence in protaper files, no significant differences were noted regarding the studied systems and sections from the apex. materials and methods in an experimental in vitro trial, 80 maxillary and mandibular first molars were selected and their cro...

o bjectives: the objective of this study was to assess the effect of new bonding techniques on enamel surface. materials and methods: sixty upper central incisors were randomly divided into two equal groups. in the first group, metal brackets were bonded using trans- bondxt and, in the second group, the same brackets were bonded with maxcemelite. the shear bond strength (sbs) of both agents to ...

Microcrystalline silicon (mc-Si:H) cells can reach efficiencies up to typically 10% and are usually incorporated in tandem micromorph devices. When cells are grown on rough substrates, ‘‘cracks’’ can appear in the mc-Si:H layers. Previous works have demonstrated that these cracks have mainly detrimental effects on the fill factor and open-circuit voltage, and act as bad diodes with a high rever...

A newly developed computational approach is proposed in the paper for the analysis of multiple crack problems based on the eigen crack opening displacement (COD) boundary integral equations. The eigen COD particularly refers to a crack in an infinite domain under fictitious traction acting on the crack surface. With the concept of eigen COD, the multiple cracks in great number can be solved by ...

In this section, we want to model a surface with flaws. We model it as a line from which N parallel cracks progress into the 2D material (see Fig. 2). The ensemble of cracks is submitted to a remote mode I loading p∞ as sketched in Fig. 2, but, because of the interactions between the cracks, each crack i (i = 1, ...N) is submitted locally to both a normal traction pi(x) and a shear traction ti(x).

The inspection of various structures often detects a fatigue cracks developed during long service life. These fatigue cracks significantly reduce remaining fatigue life and fatigue strength. Influence of the initial fatigue cracks size in non-load-carrying fillet-welded one-sided transverse attachment joints on the remaining fatigue life and fatigue strength is considered in this paper. A compu...

To model elastic wave scattering from fatigue cracks in metals, studies were conducted of wave scattering from artificial cracks using ultrasonic spectroscopy. The cracks are of two dimensional planar strips oriented at various angles and embedded in diffusion bonded titanium alloy. The crack is assumed to behave as a Griffith crack and expressions (derived by Achenbach1) to describe diffracted...