rails fracture by the growth of fatigue crack or critical crack is one of the prevalent defects in railway. the rail fracture, failure and stress analysis should be studied in order to prevention of rail fracture. in this paper, new formulation of contact stress for two rolling bodies is presented, where the results are closed to the hertz stress formulation. moreover, stress analysis is done b...

AbsractAll perilunate fracture-dislocations combine bone avulsions, ligament disruptionand fractures in different forms. The most frequent pattern is the dorsal transscaphoidperilunate fracture-dislocation. The reported risk of missed initial diagnosisin perilunate dislocations is as high as 20%. Concerning pathomechanics of theperilunate fracture-dislocation, it should be noted that most dorsa...

background: while various radiographic parameters and application of manual/gravity stress have been proposed to elucidate instability for weber b fibula fractures, the prognostic capability of these modalities remains unclear. determination of anatomic positioning of the mortise is paramount. we propose a novel view, the gravity reduction view (grv), which helps elucidate non-anatomic position...

in this paper, a finite element model is developed for the fully hydro-mechanical analysis of hydraulic fracturing in partially saturated porous media. the model is derived from the framework of generalized biot theory. the fracture propagation is governed by a cohesive fracture model. the flow within the fracture zone is modeled by the lubrication equation. the displacement of solid phase, and...

in this paper, the mean value of strain energy density criterion has been used to predict the critical fracture load in specimens with u-shaped notch under bending loads. an equation for calculation of averaged strain energy density in this zone has been presented. bending loads under mode i have been considered. two cases have been studied: 1) the control volume only includes the semicircular ...

objective : the aim of this study was to evaluate fracture characteristics of rigid two-tooth segments splinted with fiber reinforced composite (frc), with and without application of simulated masticatory forces. material and methods: in this experimental study, 80 extracted maxillary bicuspids were joined in pairs from the buccal aspect using frc. the specimens were divided into two groups. in...

hip fracture, the most dramatic complication of osteoporosis, constitutes a serious health problem of the elderly, with great socioeconomic consequences. hip fracture epidemiology has been studied by many investigators. until now, there are no reported studies in iran regarding this issue. we studied hip fractures that occurred in iran in 2003 and compared the findings with those of other count...

t-condylar fracture of the distal humerus is rare in the skeletally immature children and is very rare in young children, under 9 years of age. this fracture has been classified  as:  type a ( minimally displaced or undisplaced), type b (displaced  but  not comminuted ) and type c (displaced and comminuted). herein, we report a t-condylar fracture of the distal humerus in a 5-yr-old boy. this f...