in this study, the stability problem of a circular orthotropic cylindrical shell under the effect of anaxial compression varying with a power function of time is considered. at first, the modified donnell typedynamic stability and compatibility equations are obtained using love’s shell theory. applying the galerkinmethod and rayleigh-ritz variational techniques to these equations and taking the...

Fracture mechanics is a field of solid mechanics interested with the behaviour of materials under certain loads their distribution and finally the fracture criteria of given materials.This Paper evaluates size dependency of fracture parameters, fracture energy (Gf) and fracture process zone effective length (Cf) of concrete concluded as per Bazant’s size effect method. Fracture mechanics standa...

The competition between transverse surface and sub-surface cracks in a thin, hard coating bonded to polycarbonate substrate due to spherical indentation is investigated in real-time as a function of coating thickness and indenter radius. Fine grain (Y-TZP) and medium grain (alumina) ceramics and pre-abraded amorphous glass are used for the coating. As the coating thickness is reduced, the famil...

INTRODUCTION Distal forearm fracture is one of the most frequently observed osteoporotic fractures which may occur as a result of low energy falls such as falls from a standing height and may be linked to the osteoporotic nature of the bone especially in the elderly. In order to improve both the diagnosis of high fracture risk individuals and the fracture prevention methods, the influence of ex...

There are few informations about the influence of cusp inclination on the fracture strength of implant-supported crowns. The study aimed to evaluate the influence of cusp inclination and retention type on fracture load in implant-supported metal-ceramic single crowns. Sixty crowns were made, classified as cemented and screw-retained with screw access hole (SAH) sealed or not. Standard (33°) and...

The role of elastic mismatch in determining critical conditions for indentation fracture in brittle coatings on substrates of unlike modulus was investigated. A model transparent trilayer system, consisting of a glass coating layer bonded to a thick substrate of different glass or polymer by a thin layer of epoxy adhesive, facilitated in situ observations of crack initiation and propagation. A ...

Introduction: Since preserving the structure of treated teeth is a critical success factor, studying the effects of tooth structure loss on fracture resistance of the tooth tissue appears necessary. The aim of this study was to evaluate the consequences of the loss of different tissues regarding fracture resistance of teeth undergoing root canal treatment without the use of indirect restoration...

The purpose of the present study was to determine the relationship between cross-sectional design and fracture load using a static load bearing test in yttria-stabilized tetragonal zirconia polycrystal ceramic frameworks on a molar fixed partial denture. The test framework was designed as a 3-unit bridge with two abutment teeth at the second premolar and second molar of the mandible. The cross-...

The purpose of this study was to conduct static load-bearing tests on 4-unit Y-TZP all-ceramic fixed partial denture (FPD) frameworks with different cross-sectional areas and forms to evaluate the influence of connector design on fracture load. Each of the central, mesial and distal connectors was prepared with one of 2 different cross-sectional areas and one of 3 different forms (one circular ...

this paper aims to assess the application of support vector machine (svm) regression in order to analysis flexible pavements. to this end, 10000 four-layer flexible pavement sections consisted of asphalt concrete layer, granular base layer, granular subbase layer, and subgrade soil were analyzed under the effect of standard axle loading using multi-layered elastic theory and pavement critical r...