introduction: the aim of this study was to evaluate the effect of proximal contour of class ii composite restorations placed with straight or contoured matrix band using composite resins with different modulus of elasticity on stress distribution by finite element method. methods: in order to evaluate the stress distribution of class ii composite restorations using finite element method, upper ...

gears are one of the most critical components in power transmission system of an automobile and also many rotating machinery. many studies have been conducted on optimum gear design. the main objective is to design different aluminium metal matrix composite spur gears before and after optimization. aluminium metal matrix material composites are preferred mostly due to their low density. also th...

polymer-clay nano-composite materials, in which nano-meter thick layers of clay dispersed in polymer matrix, have generally higher mechanical properties than normal polymeric materials. a new three-dimensional unit cell model has been developed for modeling three constituent phases including inclusion, interphase and matrix. the total elastic modulus of nano-composite is evaluated.  numerical r...

in this study, aluminum (al) matrix reinforced with micro-particles (30 µm) and nano-particles (50 nm) boron carbide (b4c) were used to prepare al-2.5%wt., b4c nano-composite and micro-composite, respectively, using mechanical alloying method. the mixed powders were mechanically milled at 5, 10, 15 and 20 hrs. the xrd results indicated that the crystallite sizes of both the micro-composite and ...

Introduction: The aim of this study was to evaluate the effect of proximal contour of class II composite restorations placed with straight or contoured matrix band using composite resins with different modulus of elasticity on stress distribution by finite element method. Methods: In order to evaluate the stress distribution of class II composite restorations using finite element method, upper ...

Polymer-clay nano-composite materials, in which nano-meter thick layers of clay dispersed in polymer matrix, have generally higher mechanical properties than normal polymeric materials. A new three-dimensional unit cell model has been developed for modeling three constituent phases including inclusion, interphase and matrix. The total elastic modulus of nano-composite is evaluated.  Numerical r...

the use of methods employed for estimating the strength and toughness of composites reduces the trial-and-error in their design. the strength of interface between reinforcement and matrix and the effective surface of pulled-out particles have great influences on toughness and strength of these composites. in this study, a model was proposed to estimate the interface strength and matrix strength...

Polymer-clay nano-composite materials, in which nano-meter thick layers of clay dispersed in polymer matrix, have generally higher mechanical properties than normal polymeric materials. A new three-dimensional unit cell model has been developed for modeling three constituent phases including inclusion, interphase and matrix. The total elastic modulus of nano-composite is evaluated.  Numerical r...

In this study, aluminum (Al) matrix reinforced with micro-particles (30 µm) and nano-particles (50 nm) boron carbide (B4C) were used to prepare Al-2.5%wt., B4C nano-composite and micro-composite, respectively, using mechanical alloying method. The mixed powders were mechanically milled at 5, 10, 15 and 20 hrs. The XRD results indicated that the crystallite sizes of both the micro-composite and ...